MAX34451ETNA2+T [MAXIM]
PMBus 16-Channel V/I Monitor and 12-Channel Sequencer/Marginer;
| 型号： | MAX34451ETNA2+T |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | PMBus 16-Channel V/I Monitor and 12-Channel Sequencer/Marginer |
| 文件： | 总76页 (文件大小：2384K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
EVALUATION KIT AVAILABLE
Click here for production status of specific part numbers.
MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
General Description
Benefits and Features
The MAX34451 is a power-supply system manager
that is capable of monitoring up to 16 different voltage
rails or currents and is also capable of sequencing and
margining up to 12 power supplies. The system manager
monitors the power-supply output voltages and currents
and constantly checks them for user programmable
over and under threshold limits. If a fault is detected, the
device automatically shuts down the system in an orderly
fashion. The device can sequence the supplies in any
order at both power-up and power-down. The device has
the ability to close-loop margin the power-supply output
voltages up or down to a user-programmable level. The
device contains an internal temperature sensor and can
support up to four external remote temperature sensors.
Once configured, the device can operate autonomously
without any host intervention.
●ꢀ IntegrationꢀEnablesꢀManagementꢀofꢀMultipleꢀPowerꢀ
SuppliesꢀtoꢀMaximizeꢀSystemꢀPerformance
• 16 Channels of Voltage or Current Monitoring
• 12ꢀChannelsꢀofꢀSequencingꢀandꢀMarginingꢀ(8ꢀ
PWM,ꢀ4ꢀExternalꢀCurrentꢀDACsꢀ(1ꢀxꢀDS4424),ꢀ
andꢀSequencing
• ExpandableꢀChannelꢀOperationꢀwithꢀParallelꢀ
Devices
• RemoteꢀGroundꢀSensingꢀImprovesꢀMeasurementꢀ
Accuracy
• ProgrammableꢀUpꢀandꢀDownꢀTime-Basedꢀor
Event-BasedꢀSequencing
• DualꢀSequencingꢀLoops
• ConfigurableꢀCombinatorialꢀLogicꢀSupportingꢀUpꢀtoꢀ
16ꢀGPIsꢀandꢀ20ꢀGPOs
• AutomaticꢀClosed-LoopꢀMarginingꢀ
• NoꢀExternalꢀClockingꢀRequiredꢀ
• PMBus™-CompliantꢀCommandꢀInterface
Applications
●ꢀ NetworkꢀSwitches/Routers
●ꢀ BaseꢀStations
●ꢀ Servers
●ꢀ SmartꢀGridꢀNetworkꢀSystems
●ꢀ Fast,ꢀReliableꢀControlꢀandꢀFaultꢀDetectionꢀImprovesꢀ
SystemꢀReliability
• FastꢀMinimum/MaximumꢀThresholdꢀExcursionꢀ
Detection
• SupportsꢀUpꢀtoꢀ5ꢀTemperatureꢀSensorsꢀ(1ꢀInternalꢀ
andꢀ4ꢀRemote)
• FaultꢀDetectionꢀonꢀAllꢀTemperatureꢀSensors
• ReportsꢀPeak,ꢀMinimum,ꢀandꢀAverageꢀLevelsꢀforꢀaꢀ
NumberꢀofꢀParameters
• ProgrammableꢀAlarmꢀOutputs
• On-BoardꢀNonvolatileꢀBlackꢀBoxꢀFaultꢀLoggingꢀandꢀ
DefaultꢀConfigurationꢀSetting
PMBus is a trademark of SMIF, Inc.
2
●ꢀ I C-/SMBus-CompatibleꢀSerialꢀBusꢀwithꢀBusꢀ
Time-OutꢀFunctionꢀSimplifiesꢀAdditionalꢀTemperatureꢀ
SensorsꢀandꢀDACsꢀtoꢀtheꢀMAX34451
Ordering Information and Typical Operating Circuit appear
at end of data sheet.
●ꢀ +3.0Vꢀtoꢀ+3.6VꢀSupplyꢀVoltage
19-6642; Rev 9; 10/19
MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
TABLE OF CONTENTS
GeneralꢀDescription . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
BenefitsꢀandꢀFeatures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
AbsoluteꢀMaximumꢀRatings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
RecommendedꢀOperatingꢀConditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
PackageꢀInformation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
56ꢀTQFN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
ElectricalꢀCharacteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2
I C/SMBusꢀInterfaceꢀElectricalꢀSpecifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Typical Operating Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
TypicalꢀOperatingꢀCharacteristicsꢀ(continued) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
PinꢀConfiguration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
PinꢀDescription. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
ExpandedꢀPinꢀDescription . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
BlockꢀDiagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
DetailedꢀDescription. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
PMBus/SMBusꢀAddressꢀSelect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
SMBus/PMBusꢀOperation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
SMBus/PMBusꢀOperationꢀExamples. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
GroupꢀCommand. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
GroupꢀCommandꢀWriteꢀFormat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
ALERTꢀandꢀAlertꢀResponseꢀAddressꢀ(ARA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
AlertꢀResponseꢀAddressꢀ(ARA)ꢀByteꢀFormat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
HostꢀSendsꢀorꢀReadsꢀTooꢀFewꢀBits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
HostꢀSendsꢀorꢀReadsꢀTooꢀFewꢀBytes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
HostꢀSendsꢀTooꢀManyꢀBytesꢀorꢀBits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
HostꢀReadsꢀTooꢀManyꢀBytesꢀorꢀBits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
HostꢀSendsꢀImproperlyꢀSetꢀReadꢀBitꢀinꢀtheꢀSlaveꢀAddressꢀByte. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
UnsupportedꢀCommandꢀCodeꢀReceived/HostꢀWritesꢀtoꢀaꢀRead-OnlyꢀCommand . . . . . . . . . . . . . . . . . . . . . . . . . 26
InvalidꢀDataꢀReceived . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
HostꢀReadsꢀfromꢀaꢀWrite-OnlyꢀCommand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
SMBusꢀTimeout. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
PMBusꢀOperation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
PMBusꢀProtocolꢀSupport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
DataꢀFormat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Maxim Integrated
│ 2
www.maximintegrated.com
MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
TABLE OF CONTENTS (continued)
InterpretingꢀReceivedꢀDIRECTꢀFormatꢀValues. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
SendingꢀaꢀDIRECTꢀFormatꢀValue. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
FaultꢀManagementꢀandꢀReporting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
PasswordꢀProtection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Power-SupplyꢀSequencing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Dual-LoopꢀSequencing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Power-OnꢀSequencing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
Power-OffꢀSequencing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
SequencingꢀExample. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
MultipleꢀDeviceꢀConnections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
SEQꢀPinꢀOperation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
SystemꢀWatchdogꢀTimer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
CRCꢀMemoryꢀCheck. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
PMBusꢀCommands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
PAGEꢀ(00h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
OPERATIONꢀ(01h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
ON_OFF_CONFIGꢀ(02h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
CLEAR_FAULTSꢀ(03h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
WRITE_PROTECTꢀ(10h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
DeviceꢀConfigurationꢀDataꢀManagement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
STORE_DEFAULT_ALLꢀ(11h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
RESTORE_DEFAULT_ALLꢀ(12h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
MFR_STORE_ALLꢀ(EEh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
MFR_RESTORE_ALLꢀ(EFh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
MFR_STORE_SINGLEꢀ(FCh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
MFR_CRCꢀ(FEh). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
CAPABILITYꢀ(19h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
VOUT_MODEꢀ(20h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
VOUT_MARGIN_HIGHꢀ(25h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
VOUT_MARGIN_LOWꢀ(26h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
VOUT_SCALE_MONITORꢀ(2Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
IOUT_CAL_GAINꢀ(38h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
VOUT_OV_FAULT_LIMITꢀ(40h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
VOUT_OV_WARN_LIMITꢀ(42h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
VOUT_UV_WARN_LIMITꢀ(43h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
VOUT_UV_FAULT_LIMITꢀ(44h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
Maxim Integrated
│ 3
www.maximintegrated.com
MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
TABLE OF CONTENTS (continued)
IOUT_OC_WARN_LIMITꢀ(46h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
IOUT_OC_FAULT_LIMITꢀ(4Ah). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
OT_FAULT_LIMITꢀ(4Fh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
OT_WARN_LIMITꢀ(51h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
POWER_GOOD_ONꢀ(5Eh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
POWER_GOOD_OFFꢀ(5Fh). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
TON_DELAYꢀ(60h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
TOFF_DELAYꢀ(64h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
TON_MAX_FAULT_LIMITꢀ(62h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
STATUS_WORDꢀ(79h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
STATUS_VOUTꢀ(7Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
STATUS_IOUTꢀ(7Bh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
STATUS_TEMPERATUREꢀ(7Dh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
STATUS_CMLꢀ(7Eh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
STATUS_MFR_SPECIFICꢀ(80h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
READ_VOUTꢀ(8Bh). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
READ_IOUTꢀ(8Ch) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
READ_TEMPERATURE_1ꢀ(8Dh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
PMBUS_REVISIONꢀ(98h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
MFR_IDꢀ(99h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
MFR_MODELꢀ(9Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
MFR_REVISIONꢀ(9Bh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
MFR_LOCATIONꢀ(9Ch) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
MFR_DATEꢀ(9Dh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
MFR_SERIALꢀ(9Eh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
MFR_MODEꢀ(D1h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
MFR_PSEN_CONFIGꢀ(D2h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52
DelayꢀFunction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
MFR_VOUT_PEAKꢀ(D4h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
MFR_IOUT_PEAKꢀ(D5h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
MFR_TEMPERATURE_PEAKꢀ(D6h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
MFR_VOUT_MINꢀ(D7h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
MFR_FW_SERIALꢀ(E0h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
MFR_IOUT_AVGꢀ(E2h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
Maxim Integrated
│ 4
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
TABLE OF CONTENTS (continued)
MFR_NV_LOG_CONFIGꢀ(D8h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
MFR_FAULT_RESPONSEꢀ(D9h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56
LOCALꢀvs.ꢀGLOBALꢀChannels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56
GLOBALꢀChannelsꢀRespondꢀtoꢀFAU LTn Assertion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56
TemperatureꢀFaultꢀResponse. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56
FaultꢀDetectionꢀBeforeꢀPower-OnꢀSequencing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
LoggingꢀFaultsꢀintoꢀMFR_NV_FAULT_LOG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
AlarmꢀOutputꢀFunctionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
MFR_FAULT_RETRYꢀ(DAh). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
MFR_NV_FAULT_LOGꢀ(DCh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
MFR_TIME_COUNTꢀ(DDh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
MFR_CHANNEL_CONFIGꢀ(E4h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
MFR_TON_SEQ_MAXꢀ(E6h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68
MFR_PWM_CONFIGꢀ(E7h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
DelayꢀFunction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
MFR_SEQ_CONFIGꢀ(E8h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
MFR_MARGIN_CONFIGꢀ(DFh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Power-SupplyꢀMarginingꢀOperation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
MarginingꢀFaults. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72
DC_DACꢀValue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72
PWM/DACꢀMarginingꢀComponentꢀSelection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
TemperatureꢀSensorꢀOperation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Applications Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .74
V
, V ,ꢀandꢀREG18ꢀDecoupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
DD DDA
Open-DrainꢀPins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Keep-AliveꢀCircuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
ConfigurationꢀPort. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Resistor-DividersꢀandꢀSourceꢀImpedanceꢀforꢀRSnꢀInputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
ProtectingꢀInputꢀPins. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
ExposedꢀPadꢀGrounding. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Typical Operating Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
RevisionꢀHistory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Maxim Integrated
│ 5
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
LIST OF FIGURES
Figureꢀ1.ꢀPMBus/SMBusꢀAddressꢀSelect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Figureꢀ2.ꢀSequenceꢀControlꢀLogic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Figureꢀ3.ꢀSequencingꢀExample . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Figureꢀ4.ꢀMultipleꢀMAX34451ꢀHardwareꢀConnections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Figureꢀ5.ꢀON_OFF_CONFIGꢀLogicalꢀControl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Figureꢀ6.ꢀDeviceꢀConfigurationꢀDataꢀManagement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Figureꢀ7.ꢀStatusꢀRegisterꢀOrganization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Figureꢀ8.ꢀMFR_PSEN_CONFIGꢀFunctionalꢀLogic. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Figureꢀ9.ꢀInput-to-OutputꢀDelayꢀAction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Figureꢀ10.ꢀMFR_FAULT_RESPONSEꢀOperation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Figureꢀ11.ꢀMFR_NV_FAULT_LOG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Figureꢀ12.ꢀMFR_CHANNEL_CONFIGꢀCommand. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Figureꢀ13.ꢀMFR_PWM_CONFIGꢀFunctionalꢀLogic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Figureꢀ14.ꢀMarginingꢀHardwareꢀConfigurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
LIST OF TABLES
Tableꢀ1.ꢀPMBusꢀPAGEꢀtoꢀPin/ResourceꢀMapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Tableꢀ2.ꢀDeviceꢀChannelꢀCapabilitiesꢀandꢀOptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Tableꢀ3.ꢀPMBusꢀCommandꢀCodes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Tableꢀ3.ꢀPMBusꢀCommandꢀCodesꢀ(continued) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Tableꢀ3.ꢀPMBusꢀCommandꢀCodesꢀ(continued) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Tableꢀ4.ꢀPMBus/SMBusꢀSerial-PortꢀAddress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Tableꢀ5.ꢀPMBusꢀCommandꢀCodeꢀCoefficients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Tableꢀ6.ꢀCoefficientsꢀforꢀDIRECTꢀFormatꢀValue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Tableꢀ7.ꢀFault-MonitoringꢀStates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Tableꢀ8.ꢀOPERATIONꢀCommandꢀSequenceꢀControlꢀOptions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Tableꢀ9.ꢀPAGEꢀ(00h)ꢀCommands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Tableꢀ10.ꢀOPERATIONꢀ(01h)ꢀCommandꢀByteꢀwithꢀPAGEꢀ=ꢀ0–11ꢀ(WhenꢀBitꢀ3ꢀofꢀON_OFF_CONFIGꢀ=ꢀ1) . . . . . . . . 36
Tableꢀ11.ꢀOPERATIONꢀ(01h)ꢀCommandꢀByteꢀwithꢀPAGEꢀ=ꢀ255ꢀ(WhenꢀBitꢀ3ꢀofꢀON_OFF_CONFIGꢀ=ꢀ1) . . . . . . . . . 37
Tableꢀ12.ꢀOPERATIONꢀ(01h)ꢀCommandꢀByteꢀ(WhenꢀBitꢀ3ꢀofꢀON_OFF_CONFIGꢀ=ꢀ0) . . . . . . . . . . . . . . . . . . . . . . . 37
Tableꢀ13.ꢀON_OFF_CONFIGꢀ(02h)ꢀCommandꢀByte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Tableꢀ14.ꢀWRITE_PROTECTꢀ(10h)ꢀCommandꢀByte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Maxim Integrated
│ 6
www.maximintegrated.com
MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
LIST OF TABLES (continued)
Tableꢀ15.ꢀMemoryꢀTransferꢀPMBusꢀCommands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Tableꢀ16.ꢀMFR_CRCꢀ(FEh)ꢀCommandꢀByte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Tableꢀ17.ꢀCAPABILITYꢀ(19h)ꢀCommandꢀByte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Tableꢀ18.ꢀVOUT_SCALE_MONITORꢀ(2Ah)ꢀExamples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Tableꢀ19.ꢀSTATUS_WORDꢀ(79h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Tableꢀ20.ꢀSTATUS_VOUTꢀ(7Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Tableꢀ21.ꢀSTATUS_IOUTꢀ(7Bh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Tableꢀ22.ꢀSTATUS_TEMPERATUREꢀ(7Dh). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Tableꢀ23.ꢀSTATUS_CMLꢀ(7Eh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Tableꢀ24.ꢀSTATUS_MFR_SPECIFICꢀ(80h)ꢀ(forꢀPAGESꢀ0–11) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Tableꢀ25.ꢀSTATUS_MFR_SPECIFICꢀ(forꢀPAGEꢀ255) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Tableꢀ26.ꢀMFR_MODEꢀ(D1h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Tableꢀ27.ꢀMFR_PSEN_CONFIGꢀ(D2h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Tableꢀ28.ꢀMFR_NV_LOG_CONFIGꢀ(D8h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Tableꢀ29.ꢀFaultꢀMonitoringꢀStates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Tableꢀ30.ꢀMFR_FAULT_RESPONSEꢀ(D9h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Tableꢀ31.ꢀALARM_CONFIGꢀCodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Tableꢀ32.ꢀMFR_FAULT_RESPONSEꢀCodesꢀforꢀGLOBALꢀChannels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Tableꢀ33.ꢀMFR_FAULT_RESPONSEꢀCodesꢀforꢀLOCALꢀChannels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Tableꢀ34.ꢀMFR_NV_FAULT_LOGꢀ(DCh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Tableꢀ35.ꢀMFR_CHANNEL_CONFIGꢀ(E4h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Tableꢀ36.ꢀFault-MonitoringꢀStates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Tableꢀ37.ꢀMFR_PWM_CONFIGꢀ(E7h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Tableꢀ38.ꢀMFR_SEQ_CONFIGꢀ(E8h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Tableꢀ39.ꢀMFR_MARGIN_CONFIGꢀ(DFh). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Tableꢀ40.ꢀPower-SupplyꢀDACꢀOutputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Tableꢀ41.ꢀDS75LVꢀAddressꢀPinꢀConfiguration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .74
Tableꢀ42.ꢀMFR_TEMP_SENSOR_CONFIGꢀ(F0h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .74
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Absolute Maximum Ratings
V
and V
to V .........................................-0.3Vꢀtoꢀ+4.0V
ContinuousꢀPowerꢀDissipationꢀ(T ꢀ=ꢀ+70°C)
DD
DDA
SS
A
RSG0ꢀandꢀRSG1ꢀtoꢀV ......................................-0.3Vꢀtoꢀ+0.3V
AllꢀOtherꢀPinsꢀExceptꢀREG18
TQFNꢀ(derateꢀ27.8mW/°Cꢀaboveꢀ+70°C)...............2222.2mW
OperatingꢀTemperatureꢀRange........................... -40°Cꢀtoꢀ+85°C
StorageꢀTemperatureꢀRange............................ -55°Cꢀtoꢀ+125°C
LeadꢀTemperatureꢀ(soldering,ꢀ10s) .................................+260°C
SolderingꢀTemperatureꢀ(reflow).......................................+260°C
SS
RelativeꢀtoꢀV ....................................-0.3Vꢀtoꢀ(V ꢀ+ꢀ0.3V)*
SS
DD
REG18ꢀtoꢀV ......................................................-0.3Vꢀtoꢀ+2.0V
SS
*Subject to not exceeding +4.0V.
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these
or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect
device reliability.
Recommended Operating Conditions
(T ꢀ=ꢀ-40°Cꢀtoꢀ+85°C,ꢀunlessꢀotherwiseꢀnoted.)
A
PARAMETER
SYMBOL
CONDITIONS
MIN
3.0
TYP
MAX
UNITS
V
ꢀOperatingꢀVoltageꢀRange
V
(Noteꢀ1)
3.6
V
DD
DD
InputꢀLogicꢀ1
(ExceptꢀI2CꢀandꢀGPInꢀPins)
0.7ꢀxꢀ
V
ꢀ+ꢀ
DD
0.3
V
V
V
V
V
IH1
V
DD
InputꢀLogicꢀ0
(ExceptꢀI2CꢀandꢀGPInꢀPins)
V
-0.3
2.1
+0.3ꢀxꢀV
DD
IL1
InputꢀLogicꢀ1:ꢀSCL,ꢀSDA,
MSCL,ꢀMSDA
V
V
ꢀ+ꢀ0.3
DD
IH2
InputꢀLogicꢀ0:ꢀSCL,ꢀSDA,
MSCL,ꢀMSDA
V
-0.3
+0.8
ꢀ+ꢀ0.3
IL2
InputꢀLogicꢀ1ꢀ(GPInꢀPins)
InputꢀLogicꢀ0ꢀ(GPInꢀPins)
V
Minimum pulse width 5ms
Minimum pulse width 5ms
ADC_TIME[1:0]ꢀ=ꢀ00
ADC_TIME[1:0]ꢀ=ꢀ01
ADC_TIME[1:0]ꢀ=ꢀ10
ADC_TIME[1:0]ꢀ=ꢀ11
Fromꢀ0Vꢀtoꢀ3.0V
1.5
V
V
V
IH3
DD
V
-0.3
+1.0
1
IL3
5
SourceꢀImpedanceꢀtoꢀRSn
kΩ
10
20
4
V
V
ꢀRiseꢀTime
ms
DD
ꢀSourceꢀImpedance
10
Ω
DD
Package Information
PACKAGE TYPE: 56 TQFN
PackageꢀCodeꢀ
T5677+2
21-0144
90-0043
OutlineꢀNumber
LandꢀPatternꢀNumber
Forꢀtheꢀlatestꢀpackageꢀoutlineꢀinformationꢀandꢀlandꢀpatternsꢀ(footprints),ꢀgoꢀtoꢀwww.maximintegrated.com/packages.ꢀNoteꢀthatꢀaꢀ“+”,ꢀ
“#”,ꢀorꢀ“-”ꢀinꢀtheꢀpackageꢀcodeꢀindicatesꢀRoHSꢀstatusꢀonly.ꢀPackageꢀdrawingsꢀmayꢀshowꢀaꢀdifferentꢀsuffixꢀcharacter,ꢀbutꢀtheꢀdrawingꢀ
pertainsꢀtoꢀtheꢀpackageꢀregardlessꢀofꢀRoHSꢀstatus.
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Electrical Characteristics
(V
and V
ꢀ=ꢀ3.0Vꢀtoꢀ3.6V,ꢀT ꢀ=ꢀ-40°Cꢀtoꢀ+85°C,ꢀunlessꢀotherwiseꢀnoted.ꢀTypicalꢀvaluesꢀareꢀatꢀV /V
ꢀ=ꢀ3.3V,ꢀT ꢀ=ꢀ+25°C.)ꢀ
DD
DDA
A
DD DDA A
(Noteꢀ2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
GENERAL
I
(Noteꢀ3)
12
CPU
SupplyꢀCurrent
mA
%
I
18
PROGRAM
+25°Cꢀ<ꢀT ꢀ<ꢀ+85°C
-3
-4
+3
+4
A
SystemꢀClockꢀError
f
ERR:MOSC
-40°Cꢀ<ꢀT ꢀ<ꢀ+25°C
A
OutputꢀLogic-Low
(ExceptꢀI2CꢀPins)
V
I
I
I
ꢀ=ꢀ4mAꢀ(Noteꢀ1)
0.4
V
V
OL1
OL
OutputꢀLogic-High
(ExceptꢀI2CꢀPins)
V
=ꢀ-2mAꢀ(Noteꢀ1)
V
ꢀ-ꢀ0.5
OH1
OH
DD
OutputꢀLogic-Low:ꢀSCL,ꢀSDA,ꢀ
MSCL,ꢀMSDA
V
ꢀ=ꢀ4mAꢀ(Noteꢀ1)
OL
0.4
V
OL2
SCL,ꢀSDA,ꢀMSCL,ꢀMSDAꢀ
Leakage
IL
V
ꢀ=ꢀ0Vꢀorꢀunconnected
±5
µA
I2C
DD
CONTROL0ꢀThreshold
CONTROL0ꢀHysteresis
ADC
2.048
50
V
mV
ADCꢀBitꢀResolution
12
1000
2.048
500
15
Bits
ns
ADCꢀConversionꢀTime
ADCꢀFullꢀScale
ADC_TIME[1:0]ꢀ=ꢀ00
T ꢀ=ꢀ0°Cꢀtoꢀ+85°C
V
2.032
2.064
V
FS
A
ADCꢀMeasurementꢀResolution
RSnꢀInputꢀCapacitance
RSnꢀInputꢀLeakage
V
µV
pF
LSB
C
RS
IL
0Vꢀ<ꢀV
ꢀ<ꢀ2.1V
±0.25
±1
µA
LSB
LSB
RS
RSn
ADCꢀIntegralꢀNonlinearity
ADCꢀDifferentialꢀNonlinearity
TEMPERATURE SENSOR
INL
DNL
±1
Internal Temperature-
MeasurementꢀError
T ꢀ=ꢀ-40°Cꢀtoꢀ+85°C
±2
°C
A
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Electrical Characteristics (continued)
(V
and V
ꢀ=ꢀ3.0Vꢀtoꢀ3.6V,ꢀT ꢀ=ꢀ-40°Cꢀtoꢀ+85°C,ꢀunlessꢀotherwiseꢀnoted.ꢀTypicalꢀvaluesꢀareꢀatꢀV /V
ꢀ=ꢀ3.3V,ꢀT ꢀ=ꢀ+25°C.)ꢀ
DD
DDA
A
DD DDA A
(Noteꢀ2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
FLASH
Writeꢀ
Cycles
FlashꢀEndurance
DataꢀRetention
N
Noteꢀ3
20,000
100
FLASH
T ꢀ=ꢀ+50°Cꢀ(Noteꢀ4)
Years
ms
A
STORE_DEFAULT_ALL,ꢀ
MFR_STORE_ALLꢀWriteꢀTime
80
RESTORE_DEFAULT_ALL
WithꢀMFR_STORE_SINGLEꢀdata
WithoutꢀMFR_STORE_SINGLEꢀdata
105
500
ms
RESTORE_DEFAULT_ALLꢀorꢀ
MFR_RESTORE_ALL
µs
MFR_STORE_SINGLE
WriteꢀTime
310
11
µs
ms
ms
ms
MFR_NV_FAULT_LOG
WriteꢀTime
Writingꢀ1ꢀfaultꢀlog
MFR_NV_FAULT_LOG
DeleteꢀTime
Deletingꢀallꢀfaultꢀlogs
200
40
MFR_NV_FAULT_LOG
Overwrite Time
TIMING OPERATING CHARACTERISTICS
Thresholdꢀexcursionꢀ(Noteꢀ5)
Dataꢀcollection
64
5
µs
ms
ms
Round-RobinꢀVoltageꢀandꢀ
CurrentꢀSampleꢀRate
TemperatureꢀSampleꢀRate
DeviceꢀStartupꢀTime
1000
170
90
WithꢀMFR_STORE_SINGLEꢀdata
WithoutꢀMFR_STORE_SINGLEꢀdata
PWMꢀpower-supplyꢀmargining
PWMꢀpower-supplyꢀmargining
ms
PWMꢀFrequency
PWMꢀResolution
312.5
8
kHz
Bits
Note 1: All voltages are referenced to ground. Current entering the device are specified as positive and currents exiting the device
are negative.
Note 2:ꢀ Limitsꢀareꢀ100%ꢀproductionꢀtestedꢀatꢀT ꢀ=ꢀ+25°C.ꢀLimitsꢀoverꢀtheꢀoperatingꢀtemperatureꢀrangeꢀandꢀrelevantꢀsupplyꢀvoltageꢀ
A
rangeꢀareꢀguaranteedꢀbyꢀdesignꢀandꢀchacterization.
Note 3:ꢀ Thisꢀdoesꢀnotꢀincludeꢀpinꢀinput/outputꢀcurrents.
Note 4:ꢀ Guaranteedꢀbyꢀdesign.
Note 5:ꢀ Theꢀround-robinꢀthresholdꢀexcursionꢀrateꢀcanꢀbeꢀchangedꢀwithꢀtheꢀADC_AVERAGEꢀandꢀADC_TIMEꢀbitsꢀinꢀMFR_MODEꢀ
fromꢀ16µsꢀ(noꢀaveragingꢀandꢀ1µsꢀconversion)ꢀtoꢀ1024µsꢀ(8xꢀaveragingꢀandꢀ8µsꢀconversion).
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
2
I C/SMBus Interface Electrical Specifications
(V
and V
ꢀ=ꢀ3.0Vꢀtoꢀ3.6V,ꢀT ꢀ=ꢀ-40°Cꢀtoꢀ+85°C,ꢀunlessꢀotherwiseꢀnoted.ꢀTypicalꢀvaluesꢀareꢀatꢀV /V
ꢀ=ꢀ3.3V,ꢀT ꢀ=ꢀ+25°C.)
DD
DDA
A
DD DDA A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
kHz
SCLꢀClockꢀFrequency
MSCLꢀClockꢀFrequency
f
10
400
SCL
f
100
kHz
MSCL
BusꢀFreeꢀTimeꢀBetweenꢀSTOPꢀ
andꢀSTARTꢀConditions
t
1.3
µs
µs
BUF
HoldꢀTimeꢀ(Repeated)
STARTꢀCondition
t
0.6
HD:STA
LowꢀPeriodꢀofꢀSCL
HighꢀPeriodꢀofꢀSCL
t
1.3
0.6
0
µs
µs
LOW
t
HIGH
Receive
DataꢀHoldꢀTime
t
ns
HD:DAT
Transmit
300
100
0.6
DataꢀSetupꢀTime
t
ns
µs
ns
ns
µs
ms
SU:DAT
StartꢀSetupꢀTime
t
SU:STA
SDAꢀandꢀSCLꢀRiseꢀTime
SDAꢀandꢀSCLꢀFallꢀTime
StopꢀSetupꢀTime
t
300
300
R
t
F
t
0.6
SU:STO
ClockꢀLowꢀTimeout
t
25
27
35
TO
2
I C/SMBus Timing
SDA
t
BUF
t
F
t
SP
t
HD:STA
t
LOW
SCL
t
HIGH
t
SU:STA
t
t
R
HD:STA
t
SU:STO
t
t
SU:DAT
HD:DAT
STOP
START
REPEATED
START
NOTE: TIMING IS REFERENCED TO V
AND V
.
IL(MAX)
IH(MIN)
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Typical Operating Characteristics
(V ꢀ=ꢀ3.3VꢀandꢀT ꢀ=ꢀ+25°C,ꢀwithoutꢀMFR_STORE_SINGLEꢀdata,ꢀunlessꢀotherwiseꢀnoted.)
DD
A
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
SUPPLY CURRENT
vs. TEMPERATURE
PSENn OUTPUTS DURING POWER-UP
14.0
13.5
13.0
12.5
12.0
11.5
11.0
10.5
10.0
14.0
THE CONTROL n PIN IS ASSERTED
WHEN POWER IS APPLIED
13.5
13.0
12.5
12.0
11.5
11.0
10.5
10.0
V
DD
T
T
= +85°C
= +25°C
A
TON_DELAY =
0ms
A
PSEN0
2V/div
THE PSENn PINS
POWER UP IN A
HIGH-IMPEDANCE STATE
T
A
= -40°C
TON_DELAY =
5ms
PSEN1
20ms/div
3.0
3.1
3.2
3.3
(V)
3.4
3.5
3.6
-40 -20
0
20
40
60
80 100
V
TEMPERATURE (°C)
DD
GPOn OUTPUT PINS CONFIGURED DURING
POWER-UP (ALL PINS CONFIGURED
TO BE PUSH-PULL ACTIVE-HIGH)
FAULT PINS DURING POWER-UP
FORCE GPO ASSERTION
V
DD
V
DD
GPO
FAULT0
2V/div
2V/div
PG
PG OPERATION
ALARM OPERATION
20ms/div
FAULT2
ALARM
20ms/div
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Typical Operating Characteristics (continued)
(V ꢀ=ꢀ3.3VꢀandꢀT ꢀ=ꢀ+25°C,ꢀwithoutꢀMFR_STORE_SINGLEꢀdata,ꢀunlessꢀotherwiseꢀnoted.)
DD
A
RST PIN DURING POWER-UP
FILTERED MARGINING VOLTAGE vs. TIME
ALERT PIN DURING POWER-UP
V
100mV/div
DD
V
DD
1V/div
1V/div
RST
ALERT
40ms/div
400µs/div
400µs/div
I
vs. TIME DURING
DD
I
vs. TIME DURING A NONVOLATILE
DD
A NONVOLATILE LOG WRITE
LOG WRITE WITH OVERWRITE ENABLED
2V/div
2V/div
FAULTn
FAULTn
I
DD
I
DD
5mA/div
0mA
5mA/div
0mA
2ms/div
4ms/div
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Pin Configuration
TOP VIEW
42 41 40 39 38 37 36 35 34 33 32 31 30 29
43
44
45
46
47
48
49
50
51
52
53
54
55
56
28
27
26
25
24
23
22
21
20
19
18
17
PSEN5/GPO5
PSEN6/GPO6
PSEN7/GPO7
PSEN8/GPO8
RS13/GPI13
PSEN9/GPO9
RS12/GPI12
RS11/GPI11
RS10/GPI10
RS9/GPI9
PWM4/GPO16
PWM3/GPO15
PWM2/GPO14
PWM1/GPO13
PWM0/GPO12
N.C.
MSDA
MAX34451
MSCL
RS14/GPI14
PSEN10/GPO10/FAULT2
REG18
RS8/GPI8
RS7/GPI7
V
DD
EP/V
SS
RS6/GPI6
16 SCL
15 SDA
+
RS5/GPI5
1
2
3
4
5
6
7
8
9
10 11 12 13 14
TQFN
Pin Description
PIN*
NAME
TYPE**
AI
FUNCTION
ADCꢀVoltage-SenseꢀInputꢀ4.ꢀConnectꢀtoꢀV if unused.
RS4
SS
1
GPI4
RS3
AI
General-PurposeꢀInputꢀ4.ꢀConnectꢀtoꢀV if unused.
SS
AI
ADCꢀVoltage-SenseꢀInputꢀ3.ꢀConnectꢀtoꢀV if unused.
SS
2
3
4
GPI3
RS2
AI
General-PurposeꢀInputꢀ3.ꢀConnectꢀtoꢀV if unused.
SS
AI
ADCꢀVoltage-SenseꢀInputꢀ2.ꢀConnectꢀtoꢀV if unused.
SS
GPI2
RS1
AI
General-PurposeꢀInputꢀ2.ꢀConnectꢀtoꢀV if unused.
SS
AI
ADCꢀVoltage-SenseꢀInputꢀ1.ꢀConnectꢀtoꢀV if unused.
SS
GPI1
RS0
AI
General-PurposeꢀInputꢀ1.ꢀConnectꢀtoꢀV if unused.
SS
AI
ADCꢀVoltage-SenseꢀInputꢀ0.ꢀConnectꢀtoꢀV if unused.
SS
5
6
GPI0
AI
General-PurposeꢀInputꢀ0.ꢀConnectꢀtoꢀV if unused.
SS
Power-SupplyꢀMasterꢀOn/OffꢀControlꢀInputꢀ1.ꢀActiveꢀlowꢀorꢀactiveꢀhighꢀbasedꢀon
CONTROL1
DI
ON_OFF_CONFIGꢀcommand.ꢀConnectꢀtoꢀV if unused.
SS
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Pin Description (continued)
PIN*
NAME
TYPE**
Power
—
FUNCTION
7
8
9
V
AnalogꢀSupplyꢀVoltage.ꢀBypassꢀV
to V ꢀwithꢀ0.1µF.ꢀConnectꢀtoꢀV
.
DDA
DDA
SS
DD
N.C.
NoꢀConnection.ꢀDoꢀnotꢀconnectꢀanyꢀsignalꢀtoꢀthisꢀpin.
V
Power
GroundꢀReference.ꢀMustꢀbeꢀconnectedꢀtoꢀEPꢀ(exposedꢀpad).
SS
FaultꢀInput/Outputꢀ0.ꢀOpen-drain,ꢀactive-lowꢀI/O.ꢀSeeꢀtheꢀExpanded Pin Description
section for more details.
10
FAULT0
DIO
Power-SupplyꢀMasterꢀOn/OffꢀControlꢀInputꢀ0.ꢀActiveꢀlowꢀorꢀactiveꢀhighꢀbasedꢀon
11
12
CONTROL0
AI
ON_OFF_CONFIGꢀcommand.ꢀConnectꢀtoꢀV if unused.
SS
RST
DIO
DO
DO
Active-LowꢀResetꢀInput/Output.ꢀContainsꢀanꢀinternalꢀpullup.
Power-SupplyꢀEnableꢀ11.ꢀSeeꢀtheꢀExpanded Pin Description section for more details.
General-PurposeꢀOutputꢀ11
PSEN11
GPO11
13
SequencingꢀInput/Output.ꢀOpen-drain,ꢀactive-lowꢀI/O.ꢀThisꢀpinꢀisꢀusedꢀasꢀaꢀhandshakeꢀ
signal to coordinate sequencing in systems using multiple devices.
SEQ
DIO
RS15
GPI15
SDA
AI
AI
ADCꢀVoltage-SenseꢀInputꢀ15.ꢀConnectꢀtoꢀV if unused.
SS
14
General-PurposeꢀInputꢀ15.ꢀConnectꢀtoꢀV if unused.
SS
15
16
17
DIO
DIO
Power
I2C/SMBus-CompatibleꢀInput/Output.ꢀOpen-drainꢀoutput.
SCL
I2C/SMBus-CompatibleꢀClockꢀInput/Output.ꢀOpen-drainꢀoutput.
V
DigitalꢀSupplyꢀVoltage.ꢀBypassꢀV
to V ꢀwithꢀ0.1µF.ꢀConnectꢀtoꢀV
.
DD
DD
SS
DDA
RegulatorꢀforꢀDigitalꢀCircuitry.ꢀBypassꢀtoꢀV ꢀwithꢀ1µFꢀandꢀ10nFꢀ(500mΩꢀmaximumꢀ
SS
ESR).ꢀDoꢀnotꢀconnectꢀotherꢀcircuitryꢀtoꢀthisꢀpin.
18
REG18
Power
PSEN10
GPO10
DO
DO
Power-SupplyꢀEnableꢀ10.ꢀSeeꢀtheꢀExpanded Pin Description section for more details.
General-PurposeꢀOutputꢀ10
19
FaultꢀInput/Outputꢀ2.ꢀOpen-drain,ꢀactive-lowꢀI/O.ꢀSeeꢀtheꢀExpanded Pin Description
section for more details.
FAULT2
DIO
RS14
GPI14
MSCL
MSDA
N.C.
AI
AI
ADCꢀVoltage-SenseꢀInputꢀ14.ꢀConnectꢀtoꢀV if unused.
SS
20
General-PurposeꢀInputꢀ14.ꢀConnectꢀtoꢀV if unused.
SS
21
22
23
DIO
DIO
—
Master I2CꢀClockꢀInput/Output.ꢀOpen-drainꢀoutput.
Master I2CꢀDataꢀInput/Output.ꢀOpen-drainꢀoutput.
NoꢀInternalꢀConnection
PWM0
GPO12
PWM1
GPO13
PWM2
GPO14
PWM3
GPO15
PWM4
GPO16
DO
DO
DO
DO
DO
DO
DO
DO
DO
DO
PWMꢀMarginꢀOutputꢀ0.ꢀSeeꢀtheꢀExpanded Pin Description section for more details.
General-PurposeꢀOutputꢀ12
24
25
26
27
28
PWMꢀMarginꢀOutputꢀ1.ꢀSeeꢀtheꢀExpanded Pin Description section for more details.
General-PurposeꢀOutputꢀ13
PWMꢀMarginꢀOutputꢀ2.ꢀSeeꢀtheꢀExpanded Pin Description section for more details.
General-PurposeꢀOutputꢀ14
PWMꢀMarginꢀOutputꢀ3.ꢀSeeꢀtheꢀExpanded Pin Description section for more details.
General-PurposeꢀOutputꢀ15
PWMꢀMarginꢀOutputꢀ4.ꢀSeeꢀtheꢀExpanded Pin Description section for more details.
General-PurposeꢀOutputꢀ16
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Pin Description (continued)
PIN*
NAME
PWM5
GPO17
ALERT
TYPE**
DO
FUNCTION
PWMꢀMarginꢀOutputꢀ5.ꢀSeeꢀtheꢀExpanded Pin Description section for more details.
General-PurposeꢀOutputꢀ17
29
DO
30
DO
Alert Output. Open-drain, active-low output.
SMBusꢀSlaveꢀAddressꢀSelect.ꢀThisꢀpinꢀisꢀsampledꢀonꢀdeviceꢀpower-upꢀtoꢀdetermineꢀ
theꢀSMBusꢀaddress.ꢀSeeꢀtheꢀPMBus/SMBus Address Select section for details on how
to strap this pin to select the proper slave address.
31
32
ADDR
DI
PWM6
GPO18
PWM7
GPO19
DO
DO
DO
DO
PWMꢀMarginꢀOutputꢀ6.ꢀSeeꢀtheꢀExpanded Pin Description section for more details.
General-PurposeꢀOutputꢀ18
PWMꢀMarginꢀOutputꢀ7.ꢀSeeꢀtheꢀExpanded Pin Description section for more details.
General-PurposeꢀOutputꢀ19
33
FaultꢀInput/Outputꢀ1.ꢀOpen-drain,ꢀactive-lowꢀI/O.ꢀSeeꢀtheꢀExpanded Pin Description
section for more details.
FAULT1
DIO
34
35
36
37
RSG0
N.C.
AI
Remote-SenseꢀGroundꢀforꢀRS0/GPI0ꢀtoꢀRS3/GPI3ꢀandꢀRS12/GPI12ꢀtoꢀRS15/GPI15.
NoꢀInternalꢀConnection
—
RSG1
N.C.
AI
Remote-SenseꢀGroundꢀforꢀRS4/GPI4ꢀtoꢀRS11/GPI11.
NoꢀInternalꢀConnection
—
PSEN0
GPO0
PSEN1
GPO1
PSEN2
GPO2
PSEN3
GPO3
PSEN4
GPO4
PSEN5
GPO5
PSEN6
GPO6
PSEN7
GPO7
PSEN8
GPO8
RS13
DO
DO
DO
DO
DO
DO
DO
DO
DO
DO
DO
DO
DO
DO
DO
DO
DO
DO
AI
Power-SupplyꢀEnableꢀ0.ꢀSeeꢀtheꢀExpanded Pin Description section for more details.
General-PurposeꢀOutputꢀ0
38
39
40
41
42
43
44
45
46
47
48
Power-SupplyꢀEnableꢀ1.ꢀSeeꢀtheꢀExpanded Pin Description section for more details.
General-PurposeꢀOutputꢀ1
Power-SupplyꢀEnableꢀ2.ꢀSeeꢀtheꢀExpanded Pin Description section for more details.
General-PurposeꢀOutputꢀ2
Power-SupplyꢀEnableꢀ3.ꢀSeeꢀtheꢀExpanded Pin Description section for more details.
General-PurposeꢀOutputꢀ3
Power-SupplyꢀEnableꢀ4.ꢀSeeꢀtheꢀExpanded Pin Description section for more details.
General-PurposeꢀOutputꢀ4
Power-SupplyꢀEnableꢀ5.ꢀSeeꢀtheꢀExpanded Pin Description section for more details.
General-PurposeꢀOutputꢀ5
Power-SupplyꢀEnableꢀ6.ꢀSeeꢀtheꢀExpanded Pin Description section for more details.
General-PurposeꢀOutputꢀ6
Power-SupplyꢀEnableꢀ7.ꢀSeeꢀtheꢀExpanded Pin Description section for more details.
General-PurposeꢀOutputꢀ7
Power-SupplyꢀEnableꢀ8.ꢀSeeꢀtheꢀExpanded Pin Description section for more details.
General-PurposeꢀOutputꢀ8
ADCꢀVoltage-SenseꢀInputꢀ13.ꢀConnectꢀtoꢀV if unused.
SS
GPI13
PSEN9
GPO9
AI
General-PurposeꢀInputꢀ13.ꢀConnectꢀtoꢀV if unused.
SS
DO
DO
Power-SupplyꢀEnableꢀ9.ꢀSeeꢀtheꢀExpanded Pin Description section for more details.
General-PurposeꢀOutputꢀ9
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Pin Description (continued)
PIN*
NAME
RS12
GPI12
RS11
GPI11
RS10
GPI10
RS9
TYPE**
AI
FUNCTION
ADCꢀVoltage-SenseꢀInputꢀ12.ꢀConnectꢀtoꢀV if unused.
SS
49
AI
General-PurposeꢀInputꢀ12.ꢀConnectꢀtoꢀV if unused.
SS
AI
ADCꢀVoltage-SenseꢀInputꢀ11.ꢀConnectꢀtoꢀV if unused.
SS
50
51
52
53
54
55
AI
General-PurposeꢀInputꢀ11.ꢀConnectꢀtoꢀV if unused.
SS
AI
ADCꢀVoltage-SenseꢀInputꢀ10.ꢀConnectꢀtoꢀV if unused.
SS
AI
General-PurposeꢀInputꢀ10.ꢀConnectꢀtoꢀV if unused.
SS
AI
ADCꢀVoltage-SenseꢀInputꢀ9.ꢀConnectꢀtoꢀV if unused.
SS
GPI9
RS8
AI
General-PurposeꢀInputꢀ9.ꢀConnectꢀtoꢀV if unused.
SS
AI
ADCꢀVoltage-SenseꢀInputꢀ8.ꢀConnectꢀtoꢀV if unused.
SS
GPI8
RS7
AI
General-PurposeꢀInputꢀ8.ꢀConnectꢀtoꢀV if unused.
SS
AI
ADCꢀVoltage-SenseꢀInputꢀ7.ꢀConnectꢀtoꢀV if unused.
SS
GPI7
RS6
AI
General-PurposeꢀInputꢀ7.ꢀConnectꢀtoꢀV if unused.
SS
AI
ADCꢀVoltage-SenseꢀInputꢀ6.ꢀConnectꢀtoꢀV if unused.
SS
GPI6
RS5
AI
General-PurposeꢀInputꢀ6.ꢀConnectꢀtoꢀV if unused.
SS
AI
ADCꢀVoltage-SenseꢀInputꢀ5.ꢀConnectꢀtoꢀV if unused.
SS
56
—
GPI5
AI
General-PurposeꢀInputꢀ5.ꢀConnectꢀtoꢀV if unused.
SS
ExposedꢀPadꢀ(BottomꢀSideꢀofꢀPackage).ꢀMustꢀbeꢀconnectedꢀtoꢀlocalꢀground.
EP/V
Power
SS
Theꢀexposedꢀpadꢀisꢀtheꢀgroundꢀreferenceꢀ(V )ꢀforꢀtheꢀdevice.
SS
*All pins except the power pins, ALERT, and ADDR are high impedance during device power-up and reset.
**AI = Analog input, AO = Analog output, DI = Digital input, DIO = Digital input/output, and DO = Digital output.
Expanded Pin Description
PIN
FUNCTION
TheꢀPSEN0–PSEN11ꢀoutputsꢀareꢀprogrammableꢀwithꢀtheꢀMFR_PSEN_CONFIGꢀcommandꢀforꢀeitherꢀactive-
high or active-low operation and can be either open drain or push-pull. If not used for power-supply enables,
PSEN0–PSEN11 theseꢀoutputsꢀcanꢀbeꢀrepurposedꢀasꢀgeneral-purposeꢀoutputsꢀusingꢀtheꢀMFR_PSEN_CONFIGꢀcommand.ꢀIfꢀ
these pins are used to enable power supplies, it is highly recommended that they have external pullups or
pulldownsꢀtoꢀforceꢀtheꢀsuppliesꢀintoꢀanꢀoffꢀstateꢀwhenꢀtheꢀdeviceꢀisꢀnotꢀactive.
TheꢀPWM0–PWM7ꢀoutputsꢀareꢀhighꢀimpedanceꢀwhenꢀtheꢀmarginingꢀisꢀdisabled.ꢀAꢀ100%ꢀdutyꢀcycleꢀimpliesꢀ
PWM0–PWM7
the pins are continuously high. If not used for margining, these pins can be repurposed as general-purpose
outputsꢀwithꢀtheꢀMFR_PWM_CONFIGꢀcommand.
The FAULT0–FAULT2 pins operate independently. Any global channel can be enabled with the
MFR_FAULT_RESPONSEꢀcommandꢀtoꢀassertꢀoneꢀorꢀmoreꢀofꢀtheꢀFAULTn signals. Also, each global
channel can be enabled to shut down when one or more of the FAULTn signals asserts. These pins are used
FAULT0–FAULT2 to provide hardware control for power supplies across multiple devices. These outputs are unconditionally
deasserted while RST is asserted or the device is power cycled. After device reset and upon device power-
up, these outputs are pulled low immediately after program recall and held low until monitoring starts. Once
monitoring starts, the FAULTn signals are released if no enabled faults are present.
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Block Diagram
MSDA
MSCL
FAULT0
FAULT0
SMBus
MASTER
ENABLE
PMBus
CONTROL AND
MONITORING
ENGINE
PWM7
GPO19
FAULT1
FAULT1
ENABLE
SDA
SCL
MARGINING CONTROL
PULSE-WIDTH MODULATOR
PIN
SMBus
SLAVE
PWM0–PWM6
FUNCTION
PMBus
INTERFACE
7
16
GPO12–GPO18
SELECT
ENABLE
AND
16
ALERT
ALARMS
ADDR
RST
16
MIN/MAX
AND AVERAGE
RESULTS
POWER GOOD/GPI
ALARMS
16
PULLUP
16
NV FAULT
LOG
ALARMS
PSEN0–PSEN9
GPO0–GPO9
16
10
ENABLE
AND
PIN
V
POWER
DD
FUNCTION
SELECT
CONTROL
SEQUENCING
NV
REG18
POWER-SUPPLY ENABLE
PSEN10
GPO10
FAULT2
CONFIGURATION
1.8V
VREG
V
SS
FAULT2
SEQ
ENABLE
ENABLE
SEQUENCING
ENGINE
CONTROL1
CONTROL0
PSEN11
GPO11
SEQ
THRESHOLD EXCURSIONS
2.048V
VOLTAGE/CURRENT/TEMPERATURE
V
DDA
AUTO
SEQUENCER
MAX34451
RS0–RS3/RS12–RS15
GPI0–GPI3/GPI12–GPI15
V
DIGITAL COMPARATORS
8
REF
2.048V
UNDERVOLTAGE WARNING
UNDERVOLTAGE FAULT
OVERVOLTAGE WARNING
OVERVOLTAGE FAULT
POWER–GOOD ON
POWER–GOOD OFF
RSG0
12-BIT
1Msps
ADC
ADC
SAMPLE
AVERAGING
SRAM
MUX
RESULTS
RS4–RS11
GPI4–GPI11
8
OVERTEMPERATURE WARNING
OVERTEMPERATURE FAULT
GPI LOGIC ACTIVE–HIGH
GPI LOGIC ACTIVE–LOW
RSG1
TEMP
SENSOR
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
output and then measures the resultant output voltage.
The power-supply manager can also sequence the
supplies in any order at both power-up and power-down.
Detailed Description
The MAX34451 is a highly integrated system monitor
with functionality to monitor up to 16 different voltages or
currents and to sequence and close-loop margin up to 12
power supplies. It also supports local and remote thermal
sensing.
Thermal monitoring can be accomplished using up to five
temperature sensors including an on-chip temperature
sensorꢀ andꢀ upꢀ toꢀ fourꢀ externalꢀ remoteꢀ DS75LVꢀ digitalꢀ
temperatureꢀsensors.ꢀCommunicationsꢀwithꢀtheꢀDS75LVꢀ
temperature sensors is conducted through a dedicated
The power-supply manager monitors the power-
supply output voltage and current and constantly checks
for user-programmable overvoltage, undervoltage, and
overcurrent thresholds. It also has the ability to margin
the power-supply output voltage up or down by a user-
programmable level. The margining is performed in a
closed-loop arrangement, whereby the device automati-
callyꢀadjustsꢀaꢀPWMꢀsignalꢀorꢀanꢀexternalꢀcurrentꢀDACꢀ
2
I C/SMBusꢀinterface.
The device provides ALERT and FAULTn output signals.
HostꢀcommunicationsꢀareꢀconductedꢀthroughꢀaꢀPMBus-
compatible communications port.
Seeꢀ Table 1 and Table 2 for more details on specific
device operation.
Table 1. PMBus PAGE to Pin/Resource Mapping
PIN NAME
RSn/GPIn
PSENn/GPOn
PWMn/GPOn
(16 AVAILABLE)
(12 AVAILABLE)
(8 AVAILABLE)
PMBus
VOLTAGE
OR
CURRENT
MONITOR
GENERAL-
PURPOSE
INPUT
POWER-
SUPPLY
ENABLE
(PSEN)
GENERAL-
PURPOSE
OUTPUT
(GPO)
PWM
GENERAL-
PURPOSE
OUTPUT
(GPO)
PAGE
MARGIN
OUTPUT
(PWM)
PIN
PIN
PIN
(GPI)
0
1
RS0
RS1
GPI0
GPI1
GPI2
GPI3
GPI4
GPI5
GPI6
GPI7
GPI8
GPI9
GPI10
GPI11
GPI12
GPI13
GPI14
GPI15
5
PSEN0
PSEN1
PSEN2
PSEN3
PSEN4
PSEN5
PSEN6
PSEN7
PSEN8
PSEN9
PSEN10
PSEN11
GPO0
GPO1
GPO2
GPO3
GPO4
GPO5
GPO6
GPO7
GPO8
GPO9
GPO10
GPO11
38
39
40
41
42
43
44
45
46
48
19
13
PWM0
PWM1
PWM2
PWM3
PWM4
PWM5
PWM6
PWM7
GPO12
GPO13
GPO14
GPO15
GPO16
GPO17
GPO18
GPO19
24
25
26
27
28
29
32
33
4
2
RS2
3
3
RS3
2
4
RS4
1
5
RS5
56
55
54
53
52
51
50
49
47
20
14
6
RS6
7
RS7
8
RS8
9
RS9
Margin capability provided through
theꢀexternalꢀDS4424
10
11
12
13
14
15
RS10
RS11
RS12
RS13
RS14
RS15
CanꢀmonitorꢀvoltageꢀorꢀcurrentꢀorꢀbeꢀassignedꢀasꢀGPI
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Table 2. Device Channel Capabilities and Options
PMBus
COMMAND
PAGE
MAX34451
CHANNEL
CHANNEL CAPABILITIES
Voltage Monitor/Sequence/Margin/GPO Option:
PinsꢀRSn/GPIn,ꢀPSENn,ꢀandꢀPWMnꢀ(whereꢀnꢀ=ꢀ0–7)ꢀhaveꢀaꢀone-to-oneꢀassociationꢀforꢀeachꢀ
channelꢀthatꢀmonitorsꢀforꢀvoltageꢀ(RSn)ꢀandꢀcanꢀbeꢀusedꢀtoꢀsequenceꢀ(PSENn)ꢀandꢀmarginꢀ
(PWMn)ꢀtheꢀpowerꢀsupply.ꢀTheꢀvoltageꢀmonitoredꢀonꢀthisꢀchannelꢀcanꢀalsoꢀbeꢀconfiguredꢀtoꢀ
determine a power-good state. If not required for either sequencing or margining, the associated
PSENnꢀandꢀPWMnꢀoutputsꢀcanꢀbeꢀrepurposedꢀasꢀGPOnꢀoutputsꢀthatꢀcanꢀeitherꢀindicateꢀaꢀlogicꢀ
combinationꢀofꢀpower-goodꢀ(PG)ꢀandꢀGPIꢀstatesꢀorꢀreportꢀalarms.
Current Monitor/GPO Option:
0–7
0–7
IfꢀtheꢀRSn/GPInꢀinputꢀisꢀusedꢀtoꢀmonitorꢀcurrent,ꢀthenꢀtheꢀchannelꢀisꢀnotꢀusedꢀtoꢀsequenceꢀorꢀ
margin.ꢀTheꢀassociatedꢀPSENnꢀandꢀPWMnꢀoutputsꢀcanꢀbeꢀrepurposedꢀasꢀGPOnꢀoutputsꢀthatꢀcanꢀ
eitherꢀindicateꢀaꢀlogicꢀcombinationꢀofꢀpower-goodꢀ(PG)ꢀandꢀGPIꢀstatesꢀorꢀreportꢀalarms.
GPI/GPO Option:
IfꢀtheꢀRSn/GPInꢀinputꢀisꢀconfiguredꢀasꢀaꢀgeneral-purposeꢀinputꢀ(GPI),ꢀitꢀcanꢀbeꢀusedꢀasꢀaꢀtermꢀinꢀ
aꢀlogicꢀcombinationꢀtoꢀdetermineꢀaꢀpower-goodꢀ(PG)ꢀstateꢀandꢀassertꢀaꢀGPOnꢀoutputꢀorꢀactꢀasꢀaꢀ
conditionꢀtoꢀallowꢀaꢀpowerꢀsupplyꢀtoꢀbeꢀenabled.ꢀTheꢀassociatedꢀPSENnꢀandꢀPWMnꢀoutputsꢀcanꢀ
beꢀrepurposedꢀasꢀGPOnꢀoutputsꢀthatꢀcanꢀindicateꢀpower-goodꢀ(PG)ꢀstatesꢀorꢀreportꢀalarms.
Same as Channels 0–7 Except No PWM Outputs:
PinsꢀRSn/GPIn,ꢀandꢀPSENnꢀ(whereꢀnꢀ=ꢀ8–11)ꢀareꢀtheꢀsameꢀasꢀchannelsꢀ0–7,ꢀexceptꢀtheꢀPWMnꢀ
outputsꢀforꢀtheseꢀchannelsꢀdoꢀnotꢀexistꢀandꢀinsteadꢀtheꢀdeviceꢀusesꢀanꢀexternalꢀDS4424ꢀcurrentꢀ
DACꢀ(connectedꢀtoꢀtheꢀmasterꢀI2Cꢀlocalꢀbus)ꢀtoꢀmarginꢀtheꢀpowerꢀsupplies.ꢀTheseꢀchannelsꢀcanꢀ
alsoꢀbeꢀusedꢀtoꢀmonitorꢀcurrentꢀorꢀbeꢀusedꢀasꢀGPInꢀinputsꢀjustꢀlikeꢀchannelsꢀ0–7.
8–11
8–11
PinsꢀRSn/GPInꢀ(whereꢀnꢀ=ꢀ12–15)ꢀcannotꢀbeꢀusedꢀtoꢀcontrolꢀsequencingꢀorꢀforꢀmargining.
Voltage Monitor Option:
Monitorꢀvoltageꢀincludingꢀchannelꢀpower-goodꢀ(PG)ꢀandꢀcanꢀalsoꢀbeꢀconfiguredꢀtoꢀshutꢀdownꢀoneꢀ
or more power supplies if a fault occurs.
Current Monitor Option:
Monitorꢀcurrentꢀandꢀcanꢀbeꢀconfiguredꢀtoꢀshutꢀdownꢀoneꢀorꢀmoreꢀpowerꢀsuppliesꢀifꢀaꢀfaultꢀoccurs.
12–15
12–15
GPI Option:
Asꢀaꢀgeneral-purposeꢀinputꢀ(GPI),ꢀcanꢀbeꢀusedꢀasꢀaꢀtermꢀinꢀaꢀlogicꢀcombinationꢀtoꢀdetermineꢀaꢀ
power-goodꢀ(PG)ꢀstateꢀandꢀassertꢀaꢀGPOnꢀoutputꢀorꢀactꢀasꢀaꢀconditionꢀtoꢀallowꢀaꢀpowerꢀsupplyꢀtoꢀ
be enabled.
Maxim Integrated
│ 20
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Table 3. PMBus Command Codes
PAGE
0–11 12–15 16–20
(NOTE 1)
FLASH
STORED/
LOCKED
(NOTE 2)
DEFAULT
VALUE
(NOTE 2)
NO. OF
BYTES
CODE
COMMAND NAME
TYPE
255
00h
01h
02h
03h
10h
11h
12h
19h
20h
25h
26h
2Ah
38h
40h
42h
43h
44h
46h
4Ah
4Fh
51h
5Eh
5Fh
60h
62h
64h
79h
7Ah
7Bh
7Dh
7Eh
PAGE
R/Wꢀbyte
R/Wꢀbyte
R/Wꢀbyte
Sendꢀbyte
R/Wꢀbyte
Sendꢀbyte
Sendꢀbyte
Readꢀbyte
Readꢀbyte
R/Wꢀword
R/Wꢀword
R/Wꢀword
R/Wꢀword
R/Wꢀword
R/Wꢀword
R/Wꢀword
R/Wꢀword
R/Wꢀword
R/Wꢀword
R/Wꢀword
R/Wꢀword
R/Wꢀword
R/Wꢀword
R/Wꢀword
R/Wꢀword
R/Wꢀword
Readꢀword
Readꢀbyte
Readꢀbyte
Readꢀbyte
Readꢀbyte
R/W
R/W
R/W
W
R/W
R/W
R/W
W
1
1
1
0
1
0
0
1
1
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
1
1
1
1
N/N
N/N
Y/Y
N/N
N/Y
N/Y
N/Y
N/N
FIXED/N
Y/Y
Y/Y
Y/Y
Y/Y
Y/Y
Y/Y
Y/Y
Y/Y
Y/Y
Y/Y
Y/Y
Y/Y
Y/Y
Y/Y
Y/Y
Y/Y
Y/Y
N/N
N/N
N/N
N/N
N/N
00h
00h
OPERATION
ON_OFF_CONFIG
CLEAR_FAULTSꢀ
R/W
W
R/W
W
R/W
W
1Ah
—
WRITE_PROTECT
STORE_DEFAULT_ALLꢀ
RESTORE_DEFAULT_ALLꢀ
CAPABILITY
R/W
W
R/W
W
R/W
W
R/W
W
00h
—
W
W
W
W
—
R
R
R
R
20h/30h
40h
VOUT_MODE
R
R
R
R
VOUT_MARGIN_HIGH
VOUT_MARGIN_LOW
VOUT_SCALE_MONITOR
IOUT_CAL_GAIN
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
—
—
—
—
—
—
—
—
—
—
—
—
R/W
R/W
—
—
—
—
—
R
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
R
0000h
0000h
7FFFh
0000h
7FFFh
7FFFh
0000h
0000h
7FFFh
7FFFh
7FFFh
7FFFh
0000h
0000h
0000h
FFFFh
0000h
0000h
00h
—
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
—
VOUT_OV_FAULT_LIMIT
VOUT_OV_WARN_LIMIT
VOUT_UV_WARN_LIMIT
VOUT_UV_FAULT_LIMIT
IOUT_OC_WARN_LIMIT
IOUT_OC_FAULT_LIMIT
OT_FAULT_LIMIT
OT_WARN_LIMIT
—
—
POWER_GOOD_ON
POWER_GOOD_OFF
TON_DELAY
R/W
R/W
R/W
R/W
R/W
R
R/W
R/W
—
TON_MAX_FAULT_LIMIT
TOFF_DELAY
—
—
STATUS_WORD
R
STATUS_VOUT
R
R
—
—
R
—
—
—
R
STATUS_IOUT
R
R
00h
STATUS_TEMPERATURE
STATUS_CML
—
—
00h
R
R
R
00h
Maxim Integrated
│ 21
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Table 3. PMBus Command Codes (continued)
PAGE
FLASH
STORED/
LOCKED
(NOTE 2)
DEFAULT
VALUE
(NOTE 2)
NO. OF
BYTES
CODE
COMMAND NAME
TYPE
0–11 12–15 16–20
(NOTE 1)
255
80h
8Bh
8Ch
8Dh
98h
99h
9Ah
9Bh
9Ch
9Dh
9Eh
D1h
D2h
D4h
D5h
D6h
D7h
D8h
D9h
DAh
DCh
DDh
DFh
STATUS_MFR_SPECIFIC
READ_VOUT
Readꢀbyte
Readꢀword
Readꢀword
Readꢀword
Readꢀbyte
Readꢀbyte
Readꢀbyte
Readꢀword
R/Wꢀ64
R
R
R
R
—
—
R
—
1
2
N/N
N/N
00h
0000h
0000h
0000h
11h
READ_IOUT
R
R
—
—
2
N/N
READ_TEMPERATURE_1
PMBUS_REVISION
MFR_ID
—
—
R
—
2
N/N
R
R
R
R
1
FIXED/N
FIXED/N
FIXED/N
FIXED/N
Y/Y
R
R
R
R
1
4Dh
MFR_MODEL
R
R
R
R
1
59h
MFR_REVISION
R
R
R
R
2
(Noteꢀ3)
(Noteꢀ4)
(Noteꢀ4)
(Noteꢀ4)
0020h
(Noteꢀ5)
0000h
0000h
8000h
7FFFh
0000h
(Noteꢀ5)
0000h
(Noteꢀ6)
(Noteꢀ5)
0000h
MFR_LOCATION
R/W
R/W
R/W
R/W
R/W
R/W
R/W
—
R/W
R/W
R/W
R/W
—
R/W
R/W
R/W
R/W
—
R/W
R/W
R/W
R/W
—
8
MFR_DATE
R/Wꢀ64
8
Y/Y
MFR_SERIAL
R/Wꢀ64
8
Y/Y
MFR_MODE
R/Wꢀword
R/Wꢀ32
2
Y/Y
MFR_PSEN_CONFIG
MFR_VOUT_PEAK
MFR_IOUT_PEAK
MFR_TEMPERATURE_PEAK
MFR_VOUT_MIN
MFR_NV_LOG_CONFIG
MFR_FAULT_RESPONSE
MFR_FAULT_RETRY
MFR_NV_FAULT_LOG
MFR_TIME_COUNT
MFR_MARGIN_CONFIG
4
Y/Y
R/Wꢀword
R/Wꢀword
R/Wꢀword
R/Wꢀword
R/Wꢀword
R/Wꢀ32
R/W
R/W
—
—
—
2
N/Y
—
—
2
N/Y
R/W
—
—
2
N/Y
R/W
R/W
R/W
R/W
R
R/W
R/W
R/W
R/W
R
—
2
N/Y
R/W
R/W
2
Y/Y
4
Y/Y
R/Wꢀword
Readꢀ32
R/W
R
R/W
R
2
Y/Y
255
4
Y/Y
R/Wꢀ32
R/W
R/W
R/W
—
R/W
—
R/W
—
N/Y
R/Wꢀword
2
Y/Y
<firmwareꢀ
revision>
E0h
MFR_FW_SERIAL
Rꢀword
—
—
—
R
2
N/N
E2h
E4h
E6h
E7h
E8h
MFR_IOUT_AVG
R/Wꢀword
R/Wꢀword
R/Wꢀword
R/Wꢀ32
R
R
R/W
—
—
—
—
—
—
—
—
—
—
—
2
2
2
4
4
N/Y
Y/Y
Y/Y
Y/Y
Y/Y
0000h
0000h
MFR_CHANNEL_CONFIG
MFR_TON_SEQ_MAX
MFR_PWM_CONFIGꢀ(Noteꢀ7)
MFR_SEQ_CONFIG
R/W
R/W
R/W
R/W
0000h
—
(Noteꢀ5)
(Noteꢀ5)
R/Wꢀ32
—
Maxim Integrated
│ 22
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Table 3. PMBus Command Codes (continued)
PAGE
FLASH
STORED/
LOCKED
(NOTE 2)
DEFAULT
VALUE
(NOTE 2)
NO. OF
BYTES
CODE
COMMAND NAME
TYPE
0–11 12–15 16–20
(NOTE 1)
255
EEh
EFh
F0h
FCh
FEh
MFR_STORE_ALL
Writeꢀbyte
Writeꢀbyte
R/Wꢀword
R/Wꢀword
R/Wꢀword
W
W
W
W
W
W
W
1
1
2
2
2
N/Y
N/Y
Y/Y
N/Y
N/Y
—
MFR_RESTORE_ALL
MFR_TEMP_SENSOR_CONFIG
MFR_STORE_SINGLE
MFR_CRC
W
—
—
—
R/W
R/W
R/W
—
0000h
0000h
FFFFh
R/W
R/W
R/W
R/W
R/W
R/W
Note 1: Common commands are shaded; access through any page results in the same device response.
Note 2: In the Flash Stored/Lockedꢀcolumn,ꢀtheꢀ“N”ꢀonꢀtheꢀleftꢀindicatesꢀthatꢀthisꢀparameterꢀisꢀnotꢀstoredꢀinꢀflashꢀmemoryꢀwhenꢀ
theꢀSTORE_DEFAULT_ALLꢀorꢀMFR_STORE_ALLꢀcommandꢀisꢀexecuted;ꢀtheꢀvalueꢀshownꢀinꢀtheꢀDefault Value column is
automatically loaded upon power-on reset or when the RSTꢀpinꢀisꢀasserted.ꢀTheꢀ“Y”ꢀonꢀtheꢀleftꢀinꢀtheꢀFlash Stored/Locked
columnꢀindicatesꢀthatꢀtheꢀcurrentlyꢀloadedꢀvalueꢀinꢀthisꢀparameterꢀisꢀstoredꢀinꢀflashꢀmemoryꢀwhenꢀtheꢀSTORE_DEFAULT_
ALLꢀorꢀMFR_STORE_ALLꢀcommandꢀisꢀexecutedꢀandꢀisꢀautomaticallyꢀloadedꢀuponꢀpower-onꢀresetꢀorꢀwhenꢀtheꢀRSTꢀpinꢀisꢀ
asserted; the value shown in the Default Valueꢀcolumnꢀisꢀtheꢀvalueꢀwhenꢀshippedꢀfromꢀtheꢀfactory.ꢀ“FIXED”ꢀinꢀtheꢀFlash
Stored column means that the value is fixed at the factory and cannot be changed. The value shown in the Default Value
column is automatically loaded upon power-on reset or when the RSTꢀpinꢀisꢀasserted.ꢀTheꢀright-sideꢀY/Nꢀindicatesꢀthatꢀ
whenꢀtheꢀdeviceꢀisꢀlocked,ꢀonlyꢀtheꢀcommandsꢀlistedꢀwithꢀ“N”ꢀcanꢀbeꢀaccessed.ꢀAllꢀotherꢀcommandsꢀareꢀignoredꢀifꢀwrittenꢀ
andꢀreturnꢀFFhꢀifꢀread.ꢀOnlyꢀtheꢀPAGE,ꢀCLEAR_FAULTS,ꢀOPERATION,ꢀandꢀMFR_SERIALꢀcommandsꢀcanꢀbeꢀwrittenꢀto.ꢀ
Theꢀdeviceꢀunlocksꢀifꢀtheꢀupperꢀ4ꢀbytesꢀofꢀMFR_SERIALꢀmatchꢀtheꢀdataꢀwrittenꢀtoꢀtheꢀdevice.
Note 3: The factory-set value is dependent on the device hardware and firmware revision.
Note 4:ꢀ Theꢀfactory-setꢀdefaultꢀvalueꢀforꢀthisꢀ8-byteꢀblockꢀisꢀ3130313031303130h.
Note 5:ꢀ Theꢀfactory-setꢀdefaultꢀvalueꢀforꢀthisꢀ4-byteꢀblockꢀisꢀ00000040h.
Note 6:ꢀ Theꢀfactory-setꢀdefaultꢀvalueꢀforꢀtheꢀcompleteꢀblockꢀofꢀtheꢀMFR_NV_FAULT_LOGꢀisꢀFFh.
Note 7:ꢀ MFR_PWM_CONFIGꢀisꢀonlyꢀavailableꢀforꢀPAGESꢀ0–7.
PMBus/SMBus Address Select
Onꢀdeviceꢀpower-up,ꢀtheꢀdeviceꢀsamplesꢀtheꢀADDRꢀpinꢀ
toꢀ determineꢀ theꢀ PMBus/SMBusꢀ serial-portꢀ address.ꢀ
The combination of the components shown in Figureꢀ 1
MSDA
determinesꢀtheꢀserial-portꢀaddressꢀ(alsoꢀseeꢀTable 4).
MSCL
SMBus/PMBus Operation
MAX34451
Theꢀ deviceꢀ implementsꢀ theꢀ PMBusꢀ commandꢀ structureꢀ
R3
R4
usingꢀtheꢀSMBusꢀformat.ꢀTheꢀstructureꢀofꢀtheꢀdataꢀflowꢀ
between the host and the slave is shown below for
several different types of transactions. All transactions
begin with a host sending a command code that is
immediatelyꢀprecededꢀwithꢀaꢀ7-bitꢀslaveꢀaddressꢀ(R/Wꢀ=ꢀ
0).ꢀDataꢀisꢀsentꢀMSBꢀfirst.
R1
R2
ADDR
C2
Figure 1. PMBus/SMBus Address Select
Maxim Integrated
│ 23
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Table 4. PMBus/SMBus Serial-Port Address
R1
—
R2
220kΩ
—
R3
—
R4
—
C2
—
SLAVE ADDRESS
1110ꢀ100xꢀ(E8h)
1110ꢀ101xꢀ(EAh)
0010ꢀ010xꢀ(24h)
0010ꢀ011xꢀ(26h)
1001ꢀ100xꢀ(98h)
1001ꢀ101xꢀ(9Ah)
1011ꢀ000xꢀ(B0h)
1011ꢀ001xꢀ(B2h)
1001ꢀ110xꢀ(9Ch)
220kΩ
220kΩ
22kΩ
—
—
—
—
—
—
—
100nF
100nF
—
—
—
—
—
0kΩ
220kΩ
—
—
—
—
—
—
—
—
0kΩ
220kΩ
—
—
—
—
—
—
—
0kΩ
—
—
Note: The device also responds to a slave address of 34h (this is the factory programming address); the device should not share the
2
same I C bus with other devices that use this slave address. The letter "x" in the Slave Address column indicates the R/W bit location.
SMBus/PMBus Operation Examples
READ WORD FORMAT
1
7
1
1
8
1
1
7
1
1
8
1
8
1
1
SLAVEꢀ
ADDRESS
COMMANDꢀ
CODE
SLAVEꢀ
ADDRESS
DATAꢀBYTEꢀ
LOW
DATAꢀBYTEꢀ
HIGH
S
W
A
A
Sr
R
A
A
NA
P
READ BYTE FORMAT
1
7
1
1
8
1
1
7
1
1
8
1
1
SLAVEꢀ
ADDRESS
COMMANDꢀ
CODE
SLAVEꢀ
ADDRESS
S
W
A
A
Sr
R
A
DATAꢀBYTE NA
P
WRITE WORD FORMAT
1
7
1
1
8
1
8
1
8
1
1
SLAVEꢀ
ADDRESS
COMMANDꢀ
CODE
DATAꢀBYTEꢀ
LOW
DATAꢀBYTEꢀ
HIGH
S
W
A
A
A
A
P
KEY:
Sꢀ=ꢀSTART
WRITE BYTE FORMAT
1
7
1
1
8
1
8
1
1
Srꢀ=ꢀREPEATEDꢀSTART
Pꢀ=ꢀSTOP
SLAVEꢀ
ADDRESS
COMMANDꢀ
CODE
DATA
BYTE
S
W
A
A
A
P
Wꢀ=ꢀWRITEꢀBITꢀ(0)
Rꢀ=ꢀREADꢀBITꢀ(1)
SEND BYTE FORMAT
Aꢀ=ꢀACKNOWLEDGEꢀ(0)
NAꢀ=ꢀNOTꢀACKNOWLEDGEꢀ(1)
1
7
1
1
8
1
1
SLAVEꢀ
ADDRESS
COMMANDꢀ
CODE
S
W
A
A
P
SHADEDꢀBLOCKꢀ=ꢀSLAVEꢀTRANSACTION
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│
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
devices on the same serial bus with one long continuous
data stream. All the devices addressed during this trans-
actionꢀwaitꢀforꢀtheꢀhostꢀtoꢀissueꢀaꢀSTOPꢀbeforeꢀbeginningꢀ
to respond to the command.
Group Command
Theꢀdeviceꢀsupportsꢀtheꢀgroupꢀcommand.ꢀWithꢀtheꢀgroupꢀ
command, a host can write different data to multiple
Group Command Write Format
SLAVE ADDRESS, COMMAND BYTE, AND DATA WORD FOR DEVICE 1
1
7
1
1
8
1
8
1
8
1
SLAVEꢀ
ADDRESS
COMMANDꢀ
CODE
DATAꢀBYTEꢀ
LOW
DATAꢀBYTEꢀ
HIGH
S
W
A
A
A
A
U U U
SLAVE ADDRESS, COMMAND BYTE, AND DATA BYTE FOR DEVICE 2
1
7
1
1
8
1
8
1
SLAVEꢀ
ADDRESS
COMMANDꢀ
CODE
Sr
W
A
A
DATAꢀBYTE
A
U U U
KEY:
Sꢀ=ꢀSTART
Srꢀ=ꢀREPEATEDꢀSTART
Pꢀ=ꢀSTOP
SLAVE ADDRESS AND SEND BYTE FOR DEVICE 3
1
7
1
1
8
1
Wꢀ=ꢀWRITEꢀBITꢀ(0)
SLAVEꢀ
ADDRESS
COMMANDꢀ
CODE
Rꢀ=ꢀREADꢀBITꢀ(1)
Sr
W
A
A
U U U
Aꢀ=ꢀACKNOWLEDGEꢀ(0)
NAꢀ=ꢀNOTꢀACKNOWLEDGEꢀ(1)
SHADEDꢀBLOCKꢀ=ꢀSLAVEꢀTRANSACTION
U U U
SLAVE ADDRESS, COMMAND BYTE, AND DATA WORD FOR DEVICE N
1
7
1
1
8
1
8
1
8
1
1
SLAVEꢀ
ADDRESS
COMMANDꢀ
CODE
DATAꢀBYTEꢀ
LOW
DATAꢀBYTEꢀ
HIGH
Sr
W
A
A
A
A
P
Alert Response Address (ARA) Byte Format
Addressing
The device responds to receiving its fixed slave address
byꢀ assertingꢀ anꢀ acknowledgeꢀ (ACK)ꢀ onꢀ theꢀ bus.ꢀ Theꢀ
device does not respond to a general call address; it
only responds when it receives its fixed slave address
orꢀtheꢀalertꢀresponseꢀaddress.ꢀSeeꢀtheꢀALERT and Alert
Response Address (ARA) section for more details.
1
7
1
1
8
1
1
ARA
0001100
DEVICEꢀSLAVE
ADDRESSꢀWITHꢀꢀLSBꢀ=ꢀ0
S
R
A
NA
P
Whenꢀ theꢀ ARAꢀ isꢀ receivedꢀ andꢀ theꢀ deviceꢀ isꢀ assertingꢀ
ALERT,ꢀtheꢀdeviceꢀACKsꢀitꢀandꢀthenꢀattemptsꢀtoꢀplaceꢀitsꢀ
fixed slave address on the bus by arbitrating the bus, since
anotherꢀdeviceꢀcouldꢀalsoꢀtryꢀtoꢀrespondꢀtoꢀtheꢀARA.ꢀTheꢀ
rules of arbitration state that the lowest address device
wins. If the device wins the arbitration, it deasserts ALERT.
If the device loses arbitration, it keeps ALERT asserted and
waitsꢀforꢀtheꢀhostꢀtoꢀonceꢀagainꢀsendꢀtheꢀARA.
ALERT and Alert Response Address (ARA)
If the ALERTꢀ outputꢀ isꢀ enabledꢀ (ALERTꢀ bitꢀ =ꢀ 1ꢀ inꢀ
MFR_MODE)ꢀ whenꢀ aꢀ faultꢀ occurs,ꢀ theꢀ deviceꢀ assertsꢀ
the ALERT signal and then waits for the host to send an
ARA,ꢀ asꢀ shownꢀ inꢀ theꢀ Alert Response Address (ARA)
Byte Format section.
Maxim Integrated
│ 25
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
3)ꢀ SetsꢀtheꢀCMLꢀbitꢀinꢀSTATUS_WORD.
Host Sends or Reads Too Few Bits
If, for any reason, the host does not complete writing a full
byteꢀorꢀreadingꢀaꢀfullꢀbyteꢀfromꢀtheꢀdeviceꢀbeforeꢀaꢀSTARTꢀ
orꢀSTOPꢀisꢀreceived,ꢀtheꢀdeviceꢀdoesꢀtheꢀfollowing:
4)ꢀ SetsꢀtheꢀDATA_FAULTꢀbitꢀinꢀSTATUS_CML.
5)ꢀ NotifiesꢀtheꢀhostꢀthroughꢀALERTꢀassertionꢀ(ifꢀenabled).
Unsupported Command Code Received/Host
Writes to a Read-Only Command
If the host sends the device a command code that it does
not support, or if the host sends a command code that
isꢀnotꢀsupportedꢀbyꢀtheꢀcurrentꢀPAGEꢀsetting,ꢀtheꢀdeviceꢀ
doesꢀtheꢀfollowing:
1)ꢀ Ignoresꢀtheꢀcommand.
2)ꢀ SetsꢀtheꢀCMLꢀbitꢀinꢀSTATUS_WORD.
3)ꢀ SetsꢀtheꢀDATA_FAULTꢀbitꢀinꢀSTATUS_CML.
4)ꢀ NotifiesꢀtheꢀhostꢀthroughꢀALERTꢀassertionꢀ(ifꢀenabled).
Host Sends or Reads Too Few Bytes
1)ꢀ Ignoresꢀtheꢀcommand.
Forꢀeachꢀsupportedꢀcommand,ꢀtheꢀdeviceꢀexpectsꢀaꢀfixedꢀ
number of bytes to be written to or read from the device.
If, for any reason, less than the expected number of
bytes are written to or read from the device, the device
completely ignores the command and takes no action.
2)ꢀ SetsꢀtheꢀCMLꢀbitꢀinꢀSTATUS_WORD.
3)ꢀ SetsꢀtheꢀCOMM_FAULTꢀbitꢀinꢀSTATUS_CML.
4)ꢀ NotifiesꢀtheꢀhostꢀthroughꢀALERTꢀassertionꢀ(ifꢀenabled).
Invalid Data Received
Host Sends Too Many Bytes or Bits
TheꢀdeviceꢀchecksꢀtheꢀPAGE,ꢀOPERATION,ꢀandꢀWRITE_
PROTECTꢀ commandꢀ codesꢀ forꢀ validꢀ data.ꢀ Ifꢀ theꢀ hostꢀ
writes a data value that is invalid, the device does the
following:
Forꢀeachꢀsupportedꢀcommand,ꢀtheꢀdeviceꢀexpectsꢀaꢀfixedꢀ
number of bytes to be written to the device. If for any
reason, more than the expected number of bytes or bits is
writtenꢀtoꢀtheꢀdevice,ꢀtheꢀdeviceꢀdoesꢀtheꢀfollowing:
1)ꢀ Ignoresꢀtheꢀcommand.
1)ꢀ Ignoresꢀtheꢀcommand.
2)ꢀ SetsꢀtheꢀCMLꢀbitꢀinꢀSTATUS_WORD.
3)ꢀ SetsꢀtheꢀDATA_FAULTꢀbitꢀinꢀSTATUS_CML.
4)ꢀ NotifiesꢀtheꢀhostꢀthroughꢀALERTꢀassertionꢀ(ifꢀenabled).
2)ꢀ SetsꢀtheꢀCMLꢀbitꢀinꢀSTATUS_WORD.
3)ꢀ SetsꢀtheꢀDATA_FAULTꢀbitꢀinꢀSTATUS_CML.
4)ꢀ NotifiesꢀtheꢀhostꢀthroughꢀALERTꢀassertionꢀ(ifꢀenabled).
Host Reads from a Write-Only Command
Host Reads Too Many Bytes or Bits
Whenꢀ aꢀ readꢀ requestꢀ isꢀ issuedꢀ toꢀ aꢀ write-onlyꢀ
commandꢀ (CLEAR_FAULTS,ꢀ STORE_DEFAULT_
ALL,ꢀ RESTORE_DEFAULT_ALL,ꢀ MFR_STORE_ALL,ꢀ
MFR_RESTORE_ALL,ꢀOPERATIONꢀwithꢀPAGEꢀ=ꢀ255),ꢀ
theꢀdeviceꢀdoesꢀtheꢀfollowing:
Forꢀeachꢀsupportedꢀcommand,ꢀtheꢀdeviceꢀexpectsꢀaꢀfixedꢀ
number of bytes to be read from the device. If, for any
reason, more than the expected number of bytes or bits is
readꢀfromꢀtheꢀdevice,ꢀtheꢀdeviceꢀdoesꢀtheꢀfollowing:
1)ꢀ Sendsꢀ allꢀ onesꢀ (FFh)ꢀ asꢀ longꢀ asꢀ theꢀ hostꢀ keepsꢀ
1)ꢀ ACKsꢀtheꢀaddressꢀbyte.
2)ꢀ Ignoresꢀtheꢀcommand.
acknowledging.
2)ꢀ SetsꢀtheꢀCMLꢀbitꢀinꢀSTATUS_WORD.
3)ꢀ Sendsꢀ allꢀ onesꢀ (FFh)ꢀ asꢀ longꢀ asꢀ theꢀ hostꢀ keepsꢀ
3)ꢀ SetsꢀtheꢀDATA_FAULTꢀbitꢀinꢀSTATUS_CML.
4)ꢀ NotifiesꢀtheꢀhostꢀthroughꢀALERTꢀassertionꢀ(ifꢀenabled).
acknowledging.
4)ꢀ SetsꢀtheꢀCMLꢀbitꢀinꢀSTATUS_WORD.
Host Sends Improperly Set Read Bit in the
Slave Address Byte
IfꢀtheꢀdeviceꢀreceivesꢀtheꢀR/W bit in the slave address set
to a one immediately preceding the command code, the
deviceꢀdoesꢀtheꢀfollowingꢀ(thisꢀdoesꢀnotꢀapplyꢀtoꢀtheꢀARA):
5)ꢀ SetsꢀtheꢀDATA_FAULTꢀbitꢀinꢀSTATUS_CML.
6)ꢀ NotifiesꢀtheꢀhostꢀthroughꢀALERTꢀassertionꢀ(ifꢀenabled).
SMBus Timeout
If,ꢀ duringꢀ anꢀ activeꢀ SMBusꢀ communicationꢀ sequence,ꢀ
theꢀ SCLꢀ signalꢀ isꢀ heldꢀ lowꢀ forꢀ greaterꢀ thanꢀ theꢀ timeoutꢀ
durationꢀ (nominallyꢀ 27ms),ꢀ theꢀ deviceꢀ terminatesꢀ theꢀ
sequence and resets the serial bus. It takes no other
action.ꢀNoꢀstatusꢀbitsꢀareꢀset.
1)ꢀ ACKsꢀtheꢀaddressꢀbyte.
2)ꢀ Sendsꢀ allꢀ onesꢀ (FFh)ꢀ asꢀ longꢀ asꢀ theꢀ hostꢀ keepsꢀ
acknowledging.
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
ForꢀdetailedꢀspecificationsꢀandꢀtheꢀcompleteꢀlistꢀofꢀPMBusꢀ
commands,ꢀ referꢀ toꢀ Partꢀ IIꢀ ofꢀ theꢀ PMBusꢀ specificationꢀ
available at www.PMBus.org.ꢀ Theꢀ supportedꢀ PMBusꢀ
commands and the corresponding device behavior are
described in this document. All data values are represent-
edꢀinꢀDIRECTꢀformat,ꢀunlessꢀotherwiseꢀstated.ꢀWheneverꢀ
theꢀ PMBusꢀ specificationꢀ refersꢀ toꢀ theꢀ PMBusꢀ device,ꢀ itꢀ
is referring to the device operating in conjunction with a
powerꢀsupply.ꢀWhileꢀtheꢀcommandꢀcanꢀcallꢀforꢀturningꢀonꢀ
orꢀoffꢀtheꢀPMBusꢀdevice,ꢀtheꢀdeviceꢀalwaysꢀremainsꢀonꢀ
toꢀcontinueꢀcommunicatingꢀwithꢀtheꢀPMBusꢀmasterꢀandꢀ
transfers the command to the power supply accordingly.
PMBus Operation
Fromꢀ aꢀ softwareꢀ perspective,ꢀ theꢀ deviceꢀ appearsꢀ asꢀ aꢀ
PMBusꢀ deviceꢀ capableꢀ ofꢀ executingꢀ aꢀ subsetꢀ ofꢀ PMBusꢀ
commands.ꢀInꢀthisꢀdataꢀsheet,ꢀtheꢀtermꢀSMBusꢀisꢀusedꢀtoꢀ
referꢀ toꢀ theꢀ electricalꢀ characteristicsꢀ ofꢀ theꢀ PMBusꢀ com-
municationꢀ usingꢀ theꢀ SMBusꢀ physicalꢀ layer.ꢀ Theꢀ termꢀ
PMBusꢀisꢀusedꢀtoꢀreferꢀtoꢀtheꢀPMBusꢀcommandꢀprotocol.ꢀ
TheꢀdeviceꢀemploysꢀaꢀnumberꢀofꢀstandardꢀSMBusꢀproto-
colsꢀ(e.g.,ꢀWriteꢀWord,ꢀReadꢀWord,ꢀWriteꢀByte,ꢀReadꢀByte,ꢀ
SendꢀByte,ꢀetc.)ꢀtoꢀprogramꢀoutputꢀvoltageꢀandꢀwarning/
fault thresholds, read monitored data, and provide access
to all manufacturer-specific commands.
The device supports the group command. The group
command is used to send commands to more than one
PMBusꢀ device.ꢀ Itꢀ isꢀ notꢀ requiredꢀ thatꢀ allꢀ theꢀ devicesꢀ
receive the same command. However, no more than one
command can be sent to any one device in one group
command packet. The group command must not be used
with commands that require receiving devices to respond
withꢀdata,ꢀsuchꢀasꢀtheꢀSTATUS_WORDꢀcommand.ꢀWhenꢀ
the device receives a command through this protocol, it
immediately begins execution of the received command
afterꢀdetectingꢀtheꢀSTOPꢀcondition.
Data Format
Voltage data for commanding or reading the output
voltageꢀ orꢀ relatedꢀ parametersꢀ (suchꢀ asꢀ theꢀ overvoltageꢀ
threshold)ꢀ areꢀ presentedꢀ inꢀ DIRECTꢀ format.ꢀ DIRECTꢀ
format data is a 2-byte, two’s complement binary value.
DIRECTꢀformatꢀdataꢀcanꢀbeꢀusedꢀwithꢀanyꢀcommandꢀthatꢀ
sendsꢀorꢀreadsꢀaꢀparametricꢀvalue.ꢀTheꢀDIRECTꢀformatꢀ
uses an equation and defined coefficients to calculate
the desired values. Table 5 lists coefficients used by the
device.
Interpreting Received DIRECT Format Values
TheꢀdeviceꢀsupportsꢀtheꢀPAGEꢀcommandꢀandꢀusesꢀitꢀtoꢀ
selectꢀwhichꢀindividualꢀchannelꢀtoꢀaccess.ꢀWhenꢀaꢀdataꢀ
word is transmitted, the lower order byte is sent first
andꢀ theꢀ higherꢀ orderꢀ byteꢀ isꢀ sentꢀ last.ꢀ Withinꢀ anyꢀ byte,ꢀ
theꢀmost-significantꢀbitꢀ(MSB)ꢀisꢀsentꢀfirstꢀandꢀtheꢀleast-
significantꢀbitꢀ(LSB)ꢀisꢀsentꢀlast.
The host system uses the following equation to convert
theꢀvalueꢀreceivedꢀfromꢀtheꢀPMBusꢀdevice—inꢀthisꢀcaseꢀ
the MAX34451—into a reading of volts, degrees Celsius,
orꢀotherꢀunitsꢀasꢀappropriate:
–R
Xꢀ=ꢀ(1/m)ꢀxꢀ(Yꢀxꢀ10 ꢀ-ꢀb)
where X is the calculated real-world value in the
appropriateꢀunitsꢀ(V,ꢀ°C,ꢀetc.);ꢀmꢀisꢀtheꢀslopeꢀcoefficient;ꢀ
Yꢀisꢀtheꢀ2-byte,ꢀtwo’sꢀcomplementꢀintegerꢀreceivedꢀfromꢀ
theꢀPMBusꢀdevice;ꢀbꢀisꢀtheꢀoffset;ꢀandꢀRꢀisꢀtheꢀexponent.
PMBus Protocol Support
The device supports a subset of the commands defined
inꢀ theꢀ PMBusꢀ Powerꢀ Systemꢀ Managementꢀ Protocolꢀ
SpecificationꢀPartꢀIIꢀ-ꢀCommandꢀLanguageꢀRevisionꢀ1.1.ꢀ
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Table 5. PMBus Command Code Coefficients
PARAMETER
COMMANDS
UNITS
RESOLUTION
MAXIMUM
m
b
R
VOUT_MARGIN_HIGH
VOUT_MARGIN_LOW
VOUT_OV_FAULT_LIMIT
VOUT_OV_WARN_LIMIT
VOUT_UV_WARN_LIMIT
VOUT_UV_FAULT_LIMIT
POWER_GOOD_ON
POWER_GOOD_OFF
READ_VOUT
Voltage
mV
1
32767
1
0
0
MFR_VOUT_PEAK
MFR_VOUT_MIN
VoltageꢀScaling
VOUT_SCALE_MONITOR
—
A
1/32767
0.01
1
32767
1
0
0
0
IOUT_OC_FAULT_LIMIT
IOUT_OC_WARN_LIMIT
READ_IOUT
Current
327.67
2
MFR_IOUT_PEAK
MFR_IOUT_AVG
CurrentꢀScaling
IOUT_CAL_GAIN
mΩ
°C
0.1
3276.7
327.67
1
1
0
0
1
2
OT_FAULT_LIMIT
OT_WARN_LIMIT
READ_TEMPERATURE_1
MFR_TEMPERATURE_PEAK
Temperature
0.01
TON_DELAY
TON_MAX_FAULT_LIMIT
TOFF_DELAY
Timing
ms
0.2
6553.4
5
0
0
MFR_FAULT_RETRY
MFR_TON_SEQ_MAX
Note:ꢀ Toꢀreliablyꢀprocessꢀfault-retryꢀduringꢀsimultaneousꢀfaultꢀeventsꢀonꢀmultipleꢀchannels,ꢀitꢀisꢀrecommendedꢀtoꢀsetꢀMFR_FAULT_
RETRYꢀ≥ 1ms.
Sending a DIRECT Format Value
To send a value, the host must use the following equation
toꢀsolveꢀforꢀY:
Table 6. Coefficients for DIRECT
Format Value
COMMAND
COMMAND NAME
CODE
m
b
R
R
Yꢀ=ꢀ(mXꢀ+ꢀb)ꢀxꢀ10
whereꢀ Yꢀ isꢀ theꢀ 2-byte,ꢀ two’sꢀ complementꢀ integerꢀ toꢀ beꢀ
sent to the unit; m is the slope coefficient; X is the real-
world value, in units such as volts, to be converted for
transmission;ꢀbꢀisꢀtheꢀoffset;ꢀandꢀRꢀisꢀtheꢀexponent.
25h
VOUT_MARGIN_HIGH
READ_VOUT
1
1
0
0
0
0
8Bh
If a host wants to set the device to change the
power-supplyꢀoutputꢀvoltageꢀtoꢀ3.465Vꢀ(orꢀ3465mV),ꢀtheꢀ
correspondingꢀVOUT_MARGIN_HIGHꢀvalueꢀis:
The following example demonstrates how the host can
send and retrieve values from the device. Table 6 lists the
coefficients used in the following parameters.
0
Yꢀ=ꢀ(1ꢀxꢀ3465ꢀ+ꢀ0)ꢀxꢀ10 ꢀ=ꢀ3465ꢀ(decimal)
=ꢀ0D89hꢀ(hex)
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Conversely,ꢀifꢀtheꢀhostꢀreceivedꢀaꢀvalueꢀofꢀ0D89hꢀonꢀaꢀ
READ_VOUTꢀcommand,ꢀthisꢀisꢀequivalentꢀto:
●ꢀ Biasꢀ powerꢀ toꢀ theꢀ deviceꢀ isꢀ removedꢀ andꢀ thenꢀ
reapplied.
-(-0)
Xꢀ=ꢀ(1/1)ꢀxꢀ(0D89hꢀxꢀ10
ꢀ-ꢀ0)ꢀ=ꢀ3465mVꢀ=ꢀ3.465V
One or more latched-off power supplies are only restarted
whenꢀoneꢀofꢀtheꢀfollowingꢀoccurs:
Powerꢀ suppliesꢀ andꢀ powerꢀ convertersꢀ generallyꢀ haveꢀ
no way of knowing how their outputs are connected to
ground.ꢀ Withinꢀ theꢀ powerꢀ supply,ꢀ allꢀ outputꢀ voltagesꢀ
are most commonly treated as positive. Accordingly, all
output voltages and output-voltage-related parameters of
PMBusꢀdevicesꢀareꢀcommandedꢀandꢀreportedꢀasꢀpositiveꢀ
values. It is up to the system to know that a particular
output is negative if that is of interest to the system. All
output-voltage-related commands use 2 data bytes.
●ꢀꢀ OPERATIONꢀcommandsꢀareꢀreceivedꢀthatꢀturnꢀoffꢀandꢀ
turnꢀonꢀtheꢀpowerꢀsupplies,ꢀorꢀtheꢀCONTROLnꢀpinsꢀareꢀ
toggled to turn off and then turn on the power supplies.
●ꢀ TheꢀRST pin is toggled or a soft-reset is issued.
●ꢀ Biasꢀ powerꢀ toꢀ theꢀ deviceꢀ isꢀ removedꢀ andꢀ thenꢀ
reapplied.
The device responds to fault conditions according to
theꢀ configurationꢀ ofꢀ theꢀ MFR_FAULT_RESPONSEꢀ
command. This command determines how the device
should respond to each particular fault and whether it
should assert one or more of the FAULTn pins when a
fault occurs.
Fault Management and Reporting
Forꢀ reportingꢀ faults/warningsꢀ toꢀ theꢀ hostꢀ onꢀ aꢀ real-timeꢀ
basis, the device asserts the open-drain ALERTꢀ pinꢀ (ifꢀ
enabledꢀ inꢀ MFR_MODE)ꢀ andꢀ setsꢀ theꢀ appropriateꢀ bitꢀ inꢀ
the various status registers. On recognition of the ALERT
assertion, the host or system manager is expected to poll
TheꢀMFR_FAULT_RESPONSEꢀcommandꢀalsoꢀdeterminesꢀ
whether a channel should power up if a fault is present.
Withꢀ theꢀ RESPONSEꢀ bitsꢀ inꢀ MFR_FAULT_RESPONSE,ꢀ
each channel can be independently configured to either
respondꢀ orꢀ notꢀ respondꢀ toꢀ eachꢀ possibleꢀ fault.ꢀ Beforeꢀ
any power-supply channel is enabled, or the FAULTn
outputs deasserted, the device checks for overvoltage,
overcurrent,ꢀ andꢀ temperatureꢀ faultsꢀ (butꢀ notꢀ forꢀ
undervoltage)ꢀ ifꢀ theꢀ channelꢀ isꢀ configuredꢀ forꢀ aꢀ faultꢀ
responseꢀtoꢀeitherꢀlatchoffꢀ(RESPONSE[1:0]ꢀ=ꢀ01)ꢀorꢀretryꢀ
(RESPONSE[1:0]ꢀ=ꢀ10)ꢀinꢀtheꢀMFR_FAULT_RESPONSEꢀ
command. Only after the faults clear is the channel allowed
toꢀturnꢀon.ꢀSeeꢀTable 7 for fault-monitoring states.
2
the I C bus to determine the device asserting ALERT.
TheꢀhostꢀsendsꢀtheꢀSMBusꢀARAꢀ(0001ꢀ100).ꢀTheꢀdeviceꢀ
ACKsꢀ theꢀ SMBusꢀARA,ꢀ transmitsꢀ itsꢀ slaveꢀ address,ꢀ andꢀ
deasserts ALERT. The system controller then
communicatesꢀwithꢀPMBusꢀcommandsꢀtoꢀretrieveꢀtheꢀfault/
warning status information from the device.
Seeꢀ theꢀ individualꢀ commandꢀ sectionsꢀ forꢀ moreꢀ details.ꢀ
Faultsꢀ andꢀ warningsꢀ thatꢀ areꢀ latchedꢀ inꢀ theꢀ statusꢀ
registers are cleared when any one of the following
conditionsꢀoccur:
●ꢀ AꢀCLEAR_FAULTSꢀcommandꢀisꢀreceived.
●ꢀ TheꢀRST pin is toggled or a soft-reset is issued.
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Table 7. Fault-Monitoring States
REQUIRED DEVICE CONFIGURATION
FOR ACTIVE MONITORING
FAULT
WHEN MONITORED
•ꢀ Voltage monitoring enabled
(SELECT[5:0]ꢀ=ꢀ10hꢀorꢀ20hꢀinꢀMFR_CHANNEL_CONFIG)
Overvoltage
Continuous monitoring.
•ꢀ IfꢀSELECT[5:0]ꢀ=ꢀ10hꢀ(monitorꢀandꢀ
sequenceꢀmode),ꢀstopsꢀmonitoringꢀwhenꢀ
PSENꢀisꢀdisabled.ꢀPowerꢀGoodꢀstartsꢀ
monitoringꢀwhenꢀPSENꢀisꢀenabledꢀandꢀ
Undervoltageꢀmonitoringꢀstartsꢀwhenꢀvoltageꢀ
exceedsꢀtheꢀPOWER_GOOD_ONꢀlevel.ꢀꢀ
•ꢀ IfꢀSELECT[5:0]ꢀ=ꢀ20hꢀ(monitorꢀonlyꢀmode),ꢀ
starts monitoring when the voltage exceeds
theꢀPOWER_GOOD_ONꢀlevel.
Undervoltage/
PowerꢀGood
•ꢀ Voltage monitoring enabled
(SELECT[5:0]ꢀ=ꢀ10hꢀorꢀ20hꢀinꢀMFR_CHANNEL_CONFIG)
•ꢀ Current monitoring enabled
•ꢀ (SELECT[5:0]ꢀ=ꢀ22hꢀinꢀMFR_CHANNEL_CONFIG)
Overcurrent
Power-UpꢀTime
Overtemperature
Continuous monitoring.
•ꢀ Sequencingꢀenabled
•ꢀ (SELECT[5:0]ꢀ=ꢀ10hꢀinꢀMFR_CHANNEL_CONFIG)
Monitored only during power-on sequence.
Continuous monitoring.
•ꢀ Temperature sensor enabled
•ꢀ (ENABLEꢀ=ꢀ1ꢀinꢀMFR_TEMP_SENSOR_CONFIG)
Note: Device response to faults is determined by the configuration of MFR_FAULT_RESPONSE.
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Seeꢀ theꢀ descriptionsꢀ ofꢀ theseꢀ commandsꢀ forꢀ detailsꢀ onꢀ
theꢀexactꢀdeviceꢀconfigurationꢀrequired.ꢀPowerꢀsuppliesꢀ
canꢀbeꢀpoweredꢀupꢀandꢀdownꢀinꢀanyꢀorderꢀ(evenꢀacrossꢀ
multipleꢀ devices).ꢀ Seeꢀ theꢀ commandꢀ descriptionsꢀ andꢀ
Figureꢀ2 for specifics on sequencing control.
Password Protection
The device can be password protected by using the
LOCKꢀ bitꢀ inꢀ theꢀ MFR_MODEꢀ command.ꢀ Onceꢀ theꢀ
deviceꢀisꢀlocked,ꢀonlyꢀcertainꢀPMBusꢀcommandsꢀcanꢀbeꢀ
accessedꢀwithꢀtheꢀserialꢀport.ꢀSeeꢀTable 3 for a complete
listꢀofꢀPMBusꢀcommands.ꢀCommandsꢀthatꢀhaveꢀpasswordꢀ
protectionꢀreturnꢀallꢀonesꢀ(FFh),ꢀwithꢀtheꢀproperꢀnumberꢀ
ofꢀ dataꢀ bytes,ꢀ whenꢀ read.ꢀ Whenꢀ theꢀ deviceꢀ isꢀ locked,ꢀ
onlyꢀ theꢀ PAGE,ꢀ OPERATION,ꢀ CLEAR_FAULTS,ꢀ andꢀ
MFR_SERIALꢀcommandsꢀcanꢀbeꢀwritten;ꢀallꢀotherꢀwrittenꢀ
commandsꢀ areꢀ ignored.ꢀ Whenꢀ MFR_SERIALꢀ isꢀ writtenꢀ
and the upper 4 bytes match the internally flash-stored
value, the device unlocks and remains unlocked until the
LOCKꢀ bitꢀ inꢀ MFR_MODEꢀ isꢀ activatedꢀ onceꢀ again.ꢀ Theꢀ
LOCKꢀ statusꢀ bitꢀ inꢀ STATUS_MFR_SPECIFICꢀ isꢀ alwaysꢀ
available to indicate whether the device is locked or
unlocked.
Dual-Loop Sequencing
The device contains two independent sequencing groups,
SEQUENCE0ꢀ andꢀ SEQUENCE1.ꢀ Bothꢀ groupsꢀ doꢀ notꢀ
need to be used, but every channel is assigned to one of
theꢀtwoꢀgroupsꢀwithꢀtheꢀSEQ_SELECTꢀbitꢀinꢀtheꢀMFR_
SEQ_CONFIGꢀ command.ꢀ Theꢀ twoꢀ sequencingꢀ groupsꢀ
operateꢀindependently.ꢀSEQUENCE0ꢀisꢀalwaysꢀassociatedꢀ
withꢀCONTROL0ꢀandꢀSEQUENCE1ꢀisꢀalwaysꢀassociatedꢀ
withꢀCONTROL1.ꢀTheꢀtwoꢀsequencingꢀgroupsꢀcanꢀalsoꢀbeꢀ
independentlyꢀ controlledꢀ withꢀ theꢀ OPERATIONꢀ command.ꢀ
Withꢀ theꢀ ON_OFF_CONFIGꢀ command,ꢀ theꢀ deviceꢀ isꢀ
configuredꢀ toꢀ respondꢀ toꢀ theꢀ CONTROLnꢀ pinsꢀ orꢀ theꢀ
OPERATIONꢀcommandꢀ(orꢀboth).ꢀWhenꢀtheꢀOPERATIONꢀ
commandꢀisꢀsentꢀtoꢀtheꢀdeviceꢀ(whenꢀtheꢀPAGEꢀisꢀsetꢀtoꢀ
255),ꢀbothꢀsequenceꢀgroupsꢀareꢀcontrolled,ꢀasꢀshownꢀinꢀ
Tableꢀ8.
Power-Supply Sequencing
Sequencingꢀ controlꢀ forꢀ eachꢀ ofꢀ theꢀ 12ꢀ power-supplyꢀ
channels on the device is configured using the
MFR_SEQ_CONFIGꢀandꢀON_OFF_CONFIGꢀcommands.ꢀ
MFR_TON_SEQ_MAX
SEQ
START
STOP
SEQ MATCH
(OPTIONAL FUNCTION
OF PSEN11)
POWER–SUPPLY
ENABLES
SEQUENCE0
SEQUENCE1
POWER-ON
OPERATION COMMAND
ON
ON_OFF_CONFIG
SELECT
SELECT
J
CONTROL0
CONTROL1
PSEN0–PSEN11
OFF
K
16
PG0/GPI0–PG15/GPI15
AND
16
OR
AND
OR
MFR_SEQ_CONFIG
BITS 31:16
BIT 0
BITS 11:8
BITS 5:4
FAULT0
AND
FAULT1
(OPTIONAL FUNCTION
OF PWM7)
GLOBAL
LOCAL
GLOBAL/
LOCAL
SELECT
AND
AND
OR
FAULT2
(OPTIONAL FUNCTION
OF PSEN10)
LOCAL0–LOCAL11
MFR_FAULT_RESPONSE
BIT 24 BIT 25 BIT 26
BIT 14
NOTE: SIGNALS LISTED IN ITALICS ARE INTERNAL SIGNALS THAT CONNECT TO OTHER DEVICE FUNCTIONS. SHADED BLOCKS ARE PMBus COMMANDS.
Figure 2. Sequence Control Logic
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Table 8. OPERATION Command Sequence Control Options
OPERATION COMMAND (PAGE = 255)
GROUP
ON
SOFT-OFF
40hꢀorꢀ41h
40hꢀorꢀ42h
IMMEDIATE OFF
00hꢀorꢀ01h
SEQUENCE0
80hꢀorꢀ81h
80hꢀorꢀ82h
SEQUENCE1
00hꢀorꢀ02h
all the power supplies can be switched off immediately,
asꢀconfiguredꢀinꢀtheꢀON_OFF_CONFIGꢀcommandꢀorꢀwithꢀ
theꢀOPERATIONꢀcommand.
Power-On Sequencing
Theꢀactivationꢀofꢀallꢀpower-supplyꢀchannelsꢀ(evenꢀacrossꢀ
multipleꢀ devices)ꢀ isꢀ initiatedꢀ fromꢀ aꢀ commonꢀ STARTꢀ
signalꢀthatꢀcanꢀeitherꢀbeꢀtheꢀCONTROL0ꢀorꢀCONTROL1ꢀ
pin,ꢀ orꢀ theꢀ OPERATIONꢀ command.ꢀ Eachꢀ power-supplyꢀ
channel on the device can be sequenced on by one of the
followingꢀmethods:
Asꢀ configuredꢀ withꢀ theꢀ ON_OFF_CONFIGꢀ command,ꢀ
eitherꢀ theꢀ CONTROL0ꢀ orꢀ CONTROL1ꢀ pinꢀ orꢀ theꢀ
OPERATIONꢀ commandꢀ isꢀ theꢀ masterꢀ offꢀ switch.ꢀ Whenꢀ
eitherꢀtheꢀCONTROL0ꢀorꢀCONTROL1ꢀpinꢀgoesꢀinactive,ꢀ
orꢀtheꢀOPERATIONꢀoffꢀcommandꢀisꢀreceivedꢀ(orꢀoneꢀofꢀ
the enabled FAULTnꢀpinsꢀasserted),ꢀtheꢀpowerꢀsuppliesꢀ
areꢀsequencedꢀoff.ꢀNeitherꢀtheꢀpower-goodꢀ(PG)ꢀorꢀGPIꢀ
logic combinations, nor the SEQ pin, can be used to turn
off the power supplies.
●ꢀ Powerꢀisꢀappliedꢀtoꢀtheꢀdevice.
●ꢀ TheꢀCONTROL0ꢀpinꢀgoesꢀactive.
●ꢀ TheꢀCONTROL1ꢀpinꢀgoesꢀactive.
●ꢀ TheꢀOPERATIONꢀcommandꢀisꢀreceived.
●ꢀ TheꢀlogicꢀcombinationꢀofꢀpowerꢀgoodsꢀandꢀGPIꢀisꢀvalid.
●ꢀ TheꢀSEQ pin signal is matched.
Sequencing Example
As an example, Figureꢀ 3 details a simple sequencing
scheme consisting of four power supplies using a mixture
ofꢀ time-basedꢀ andꢀ event-basedꢀ sequencing.ꢀ Channelsꢀ 0ꢀ
and 2 use time-based sequencing and channels 1 and 5
useꢀevent-basedꢀsequencing.ꢀWhenꢀeitherꢀtheꢀCONTROL0ꢀ
orꢀ CONTROL1ꢀ pinꢀ goesꢀ active,ꢀ orꢀ theꢀ OPERATIONꢀ
commandꢀ isꢀ receivedꢀ (asꢀ definedꢀ byꢀ theꢀ ON_OFF_
CONFIGꢀcommand),ꢀPSEN0ꢀisꢀassertedꢀafterꢀtheꢀdelayꢀtimeꢀ
configuredꢀ inꢀ TON_DELAY.ꢀ RS0ꢀ isꢀ monitoredꢀ toꢀ ensureꢀ
thatꢀ theꢀ PSEN0ꢀ supplyꢀ crossesꢀ theꢀ power-good-onꢀ
levelꢀ (asꢀ configuredꢀ inꢀ POWER_GOOD_ON)ꢀ withinꢀ aꢀ
programmableꢀ timeꢀ limitꢀ (asꢀ configuredꢀ inꢀ TON_MAX_
FAULT_LIMIT).ꢀ PSEN2ꢀ operatesꢀ inꢀ aꢀ similarꢀ fashionꢀ asꢀ
PSEN0,ꢀbutꢀwithꢀaꢀdifferentꢀTON_DELAYꢀandꢀaꢀdifferentꢀ
TON_MAX_FAULT_LIMIT.ꢀSinceꢀtheꢀpower-upꢀofꢀchannelsꢀ
0ꢀ andꢀ 2ꢀ areꢀ basedꢀ solelyꢀ onꢀ theirꢀ TON_DELAYꢀ values,ꢀ
these channels are time-based.
Eachꢀ enabledꢀ PSENnꢀ outputꢀ goesꢀ activeꢀ (eitherꢀ activeꢀ
highꢀorꢀactiveꢀlow,ꢀasꢀdefinedꢀinꢀMFR_PSEN_CONFIG)ꢀ
afterꢀ theꢀ associatedꢀ delayꢀ timeꢀ programmedꢀ inꢀ TON_
DELAY.ꢀ Theꢀ powerꢀ suppliesꢀ canꢀ beꢀ sequencedꢀ onꢀ inꢀ
anyꢀ order.ꢀ Eachꢀ channelꢀ canꢀ beꢀ sequencedꢀ onꢀ withꢀ
either time-based or event-based conditions. The output
voltage of each power supply is monitored to ensure that
theꢀ supplyꢀ crossesꢀ theꢀ power-good-onꢀ levelꢀ (asꢀ con-
figuredꢀ inꢀ theꢀ POWER_GOOD_ONꢀ command)ꢀ withinꢀ aꢀ
programmableꢀtimeꢀlimit,ꢀasꢀconfiguredꢀinꢀtheꢀTON_MAX_
FAULT_LIMITꢀ command.ꢀ Thisꢀ power-upꢀ timeꢀ limitꢀ canꢀ
beꢀ disabledꢀ byꢀ configuringꢀ TON_MAX_FAULT_LIMITꢀ toꢀ
0000h.ꢀForꢀchannelsꢀusingꢀevent-basedꢀsequencing,ꢀtheꢀ
MFR_TON_SEQ_MAXꢀ commandꢀ determinesꢀ theꢀ maxi-
mumꢀtimeꢀlimitꢀforꢀtheꢀsequence-onꢀeventꢀtoꢀoccur.ꢀLikeꢀ
theꢀTON_MAX_FAULT_LIMIT,ꢀthisꢀlimitꢀcanꢀbeꢀdisabledꢀ
byꢀconfiguringꢀMFR_TON_SEQ_MAXꢀtoꢀ0000h.ꢀThereꢀisꢀ
aꢀone-to-oneꢀcorrespondenceꢀbetweenꢀtheꢀRSnꢀinputsꢀandꢀ
theꢀPSENnꢀoutputs.ꢀForꢀexample,ꢀRS6ꢀmonitorsꢀtheꢀpowerꢀ
supplyꢀ controlledꢀ byꢀ PSEN6.ꢀAllꢀ power-onꢀ sequencingꢀ isꢀ
gatedꢀbyꢀdetectedꢀfaults.ꢀBeforeꢀanyꢀpower-supplyꢀchannelꢀ
isꢀenabledꢀ(orꢀtheꢀFAULTnꢀoutputꢀdeasserted)ꢀtheꢀdeviceꢀ
checks for overvoltage, overcurrent, and temperature
faultsꢀthatꢀareꢀenabledꢀ(butꢀnotꢀforꢀundervoltageꢀsinceꢀtheꢀ
supplyꢀisꢀoff).
Whenꢀ RS2ꢀ crossesꢀ itsꢀ power-good-onꢀ level,ꢀ PSEN5ꢀ isꢀ
assertedꢀ afterꢀ itsꢀ configuredꢀTON_DELAYꢀ andꢀ similarly,ꢀ
PSEN1ꢀ assertsꢀ whenꢀ RS5ꢀ crossesꢀ itsꢀ power-good-onꢀ
level.ꢀSinceꢀtheꢀpower-upꢀofꢀchannelsꢀ5ꢀandꢀ1ꢀareꢀbasedꢀ
on the power-good states of other channels, these
channelsꢀ areꢀ event-based.ꢀ Theꢀ MFR_TON_SEQ_MAXꢀ
command can be used to ensure that these events occur
and the power-up sequence does not hang waiting for an
eventꢀtoꢀtranspire.ꢀWhenꢀRS1ꢀcrossesꢀitsꢀpower-good-onꢀ
level, it has been configured to generate a SEQ pin signal
to communicate to another device to turn on one or more
of its power supplies.
Power-Off Sequencing
The order in which the supplies are disabled is deter-
minedꢀwithꢀtheꢀTOFF_DELAYꢀconfiguration.ꢀAlternatively,ꢀ
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
POWER-UP
POWER-DOWN
NOTES 1 AND 2
CONTROL0/1 PIN
OR OPERATION COMMAND
TON_DELAY
TOFF_DELAY
TOFF_DELAY
TON_MAX_FAULT_LIMIT
POWER_GOOD_ON
PSEN0
RS0
TON_DELAY
TON_MAX_FAULT_LIMIT
PSEN2
RS2
POWER_GOOD_ON
TON_DELAY
TOFF_DELAY
TOFF_DELAY
TON_MAX_FAULT_LIMIT
PSEN5
RS5
POWER_GOOD_ON
TON_DELAY
TON_MAX_FAULT_LIMIT
PSEN1
POWER_GOOD_ON
RS1
SEQ
NOTES: 1. ALTERNATE POWER-DOWN SEQUENCING OPERATION IS TO SHUT OFF ALL SUPPLIES IMMEDIATELY.
2. THE FAULTn PIN BEING ASSERTED LOW CAN ALSO CAUSE A POWER-DOWN SEQUENCE TO OCCUR.
Figure 3. Sequencing Example
to one or more of the FAULTn signals. The FAULT0 signal
is always available, whereas FAULT1 and FAULT2 are
optionalꢀsignals.ꢀWhenꢀtheyꢀareꢀenabled,ꢀtheꢀPWM7ꢀandꢀ
PSEN10ꢀoutputsꢀ(respectively)ꢀareꢀdisabled.ꢀTheꢀuseꢀofꢀ
multiple fault signals allows more flexibility in controlling
which power supplies need to shut down during a fault.
Multiple Device Connections
Multiple MAX34451 devices can be connected together to
increase the system channel count. Figureꢀ4 details the
recommended connection scheme.
Allꢀ theꢀ paralleledꢀ devicesꢀ shareꢀ theꢀ sameꢀ CONTROLn,ꢀ
FAULTn, SEQ,ꢀandꢀSMBusꢀsignals.ꢀTheꢀdevicesꢀallꢀuseꢀ
aꢀcommonꢀsignalꢀ(eitherꢀtheꢀCONTROL0ꢀorꢀCONTROL1ꢀ
pin,ꢀorꢀtheꢀOPERATIONꢀcommand)ꢀtoꢀenable/disableꢀallꢀ
the power supplies. Any of the monitored power supplies
canꢀ beꢀ configuredꢀ withꢀ theꢀ MFR_FAULT_RESPONSEꢀ
command to activate one or more of the FAULTn signals
and shut down all the other supplies enabled to respond
USER NOTE:
●ꢀ Allꢀ devicesꢀ mustꢀ beꢀ configuredꢀ withꢀ theꢀ sameꢀ ON_
OFF_CONFIGꢀconfiguration.ꢀ
● All devices must be powered up and reset at the same
time.
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
SEQ Pin Operation
The SEQꢀpinꢀisꢀanotherꢀoptionalꢀsignal.ꢀWhenꢀthisꢀfunctionꢀ
is enabled, it allows multiple devices to coordinate event-
basedꢀ sequencing.ꢀ Withꢀ theꢀ MFR_CHANNEL_CONFIGꢀ
command, any channel can be configured to generate one
ofꢀ 15ꢀ signatures.ꢀ Whenꢀ theꢀ channelꢀ crossesꢀ itsꢀ power-
good-on level, it generates the needed SEQ signature
ifꢀ soꢀ enabled.ꢀ Withꢀ theꢀ MFR_SEQ_CONFIGꢀ command,ꢀ
anyꢀ ofꢀ theꢀ sequencingꢀ channelsꢀ (PAGESꢀ 0–11)ꢀ canꢀ beꢀ
configured to wait for a match on the SEQ pin before assert-
ingꢀtheꢀPSENnꢀoutput.ꢀToꢀensureꢀthatꢀaꢀvalid SEQ signal is
received when it should be, the maximum allowable time is
configuredꢀintoꢀtheꢀMFR_TON_SEQ_MAXꢀcommand.
MAX34451
PMBus
SCL/SDA (UNIQUE ADDRESS)
CONTROL
CONTROL0
CONTROL1
HARDWARE
CONTROL
FAULT0
FAULT1 (OPTIONAL)
FAULT2 (OPTIONAL)
SEQ (OPTIONAL)
USER NOTE:
●
Only one channel should be configured to generate
any one particular SEQ signature. If two channels
generate the same signature, they might reach their
power-good-on levels at different times and corrupt the
SEQ signal.
MAX34451
SCL/SDA (UNIQUE ADDRESS)
CONTROL0
CONTROL1
●
Allow more than 15ms between consecutive SEQ
FAULT0
FAULT1 (OPTIONAL)
FAULT2 (OPTIONAL)
signatures.
System Watchdog Timer
SEQ (OPTIONAL)
The device uses an internal watchdog timer. This timer
is internally reset every 5ms. In the event the device is
locked up, and the watchdog reset does not occur after
210ms,ꢀtheꢀdeviceꢀisꢀautomaticallyꢀreset.ꢀAfterꢀtheꢀresetꢀ
occurs, the device reloads all configuration values that
were stored to flash and begins normal operation. After
theꢀreset,ꢀtheꢀdeviceꢀalsoꢀdoesꢀtheꢀfollowing:
MAX34451
SCL/SDA (UNIQUE ADDRESS)
CONTROL0
CONTROL1
1)ꢀ SetsꢀtheꢀMFRꢀbitꢀinꢀSTATUS_WORD.
FAULT0
FAULT1 (OPTIONAL)
FAULT2 (OPTIONAL)
2)ꢀ Setsꢀ theꢀ WATCHDOG_INTꢀ bitꢀ inꢀ STATUS_MFR_
SPECIFICꢀ(forꢀPAGEꢀ255).
3)ꢀ NotifiesꢀtheꢀhostꢀthroughꢀALERTꢀassertionꢀ(ifꢀenabledꢀ
SEQ (OPTIONAL)
inꢀMFR_MODE).
CRC Memory Check
Uponꢀreset,ꢀtheꢀdeviceꢀrunsꢀanꢀinternalꢀalgorithmꢀtoꢀcheckꢀ
the integrity of the key internal nonvolatile memory. If
theꢀCRCꢀcheckꢀfails,ꢀtheꢀdeviceꢀdoesꢀnotꢀpowerꢀupꢀandꢀ
remains in a null state with all pins high impedance but
asserts the FAULT0 output.
Figure 4. Multiple MAX34451 Hardware Connections
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
PAGEꢀcommandꢀwithꢀdataꢀ0–20ꢀ(decimal)ꢀtoꢀselectꢀwhichꢀ
power supply or temperature sensor is affected by all the
followingꢀ PMBusꢀ commands.ꢀ Notꢀ allꢀ commandsꢀ areꢀ
supported within each page. If an unsupported command
isꢀ received,ꢀ theꢀ CMLꢀ statusꢀ bitꢀ isꢀ set.ꢀ Someꢀ commandsꢀ
are common, which means that any selected page has the
same effect on and the same response from the device.
SeeꢀTable 9ꢀforꢀPAGEꢀcommands.
PMBus Commands
Aꢀ summaryꢀ ofꢀ theꢀ PMBusꢀ commandsꢀ supportedꢀ byꢀ theꢀ
device are described in the following sections.
PAGE (00h)
The device can monitor up to 16 voltages or currents,
sequence up to 12 power supplies, and margin up to
12 power supplies. The device can monitor up to five
temperature sensors, one internal local tempera-
ture sensor, plus four external remote temperature
sensorsꢀ (DS75LV).ꢀ Allꢀ theꢀ monitoringꢀ andꢀ controlꢀ isꢀ
Setꢀ theꢀ PAGEꢀ toꢀ 255ꢀ whenꢀ theꢀ followingꢀ PMBusꢀ
commands should apply to all pages at the same time.
Thereꢀareꢀonlyꢀaꢀfewꢀcommandsꢀ(OPERATION,ꢀCLEAR_
FAULTS)ꢀwhereꢀthisꢀfunctionꢀhasꢀaꢀrealꢀapplication.
2
accomplishedꢀusingꢀoneꢀPMBusꢀ(I C)ꢀaddress.ꢀSendꢀtheꢀ
Table 9. PAGE (00h) Commands
PAGE*
ASSOCIATED CONTROL
PowerꢀsupplyꢀmonitoredꢀbyꢀRS0,ꢀcontrolledꢀbyꢀPSEN0,ꢀandꢀmarginedꢀwithꢀPWM0.
0
1
2
3
4
5
6
7
PowerꢀsupplyꢀmonitoredꢀbyꢀRS1,ꢀcontrolledꢀbyꢀPSEN1,ꢀandꢀmarginedꢀwithꢀPWM1.
PowerꢀsupplyꢀmonitoredꢀbyꢀRS2,ꢀcontrolledꢀbyꢀPSEN2,ꢀandꢀmarginedꢀwithꢀPWM2.
PowerꢀsupplyꢀmonitoredꢀbyꢀRS3,ꢀcontrolledꢀbyꢀPSEN3,ꢀandꢀmarginedꢀwithꢀPWM3.
PowerꢀsupplyꢀmonitoredꢀbyꢀRS4,ꢀcontrolledꢀbyꢀPSEN4,ꢀandꢀmarginedꢀwithꢀPWM4.
PowerꢀsupplyꢀmonitoredꢀbyꢀRS5,ꢀcontrolledꢀbyꢀPSEN5,ꢀandꢀmarginedꢀwithꢀPWM5.
PowerꢀsupplyꢀmonitoredꢀbyꢀRS6,ꢀcontrolledꢀbyꢀPSEN6,ꢀandꢀmarginedꢀwithꢀPWM6.
PowerꢀsupplyꢀmonitoredꢀbyꢀRS7,ꢀcontrolledꢀbyꢀPSEN7,ꢀandꢀmarginedꢀwithꢀPWM7.
PowerꢀsupplyꢀmonitoredꢀbyꢀRS8,ꢀcontrolledꢀbyꢀPSEN8,ꢀandꢀoptionallyꢀmarginedꢀbyꢀOUT0ꢀofꢀexternal
DS4424ꢀatꢀI2CꢀaddressꢀA0h.
8
9
PowerꢀsupplyꢀmonitoredꢀbyꢀRS9,ꢀcontrolledꢀbyꢀPSEN9,ꢀandꢀoptionallyꢀmarginedꢀbyꢀOUT1ꢀofꢀexternal
DS4424ꢀatꢀI2CꢀaddressꢀA0h.
PowerꢀsupplyꢀmonitoredꢀbyꢀRS10,ꢀcontrolledꢀbyꢀPSEN10,ꢀandꢀoptionallyꢀmarginedꢀbyꢀOUT2ꢀofꢀexternal
DS4424ꢀatꢀI2CꢀaddressꢀA0h.
10
11
PowerꢀsupplyꢀmonitoredꢀbyꢀRS11,ꢀcontrolledꢀbyꢀPSEN11,ꢀandꢀoptionallyꢀmarginedꢀbyꢀOUT3ꢀofꢀexternal
DS4424ꢀatꢀI2CꢀaddressꢀA0h.
12
13
ADCꢀchannelꢀ12ꢀ(monitorsꢀvoltageꢀorꢀcurrent)ꢀorꢀGPI.
ADCꢀchannelꢀ13ꢀ(monitorsꢀvoltageꢀorꢀcurrent)ꢀorꢀGPI.
ADCꢀchannelꢀ14ꢀ(monitorsꢀvoltageꢀorꢀcurrent)ꢀorꢀGPI.
ADCꢀchannelꢀ15ꢀ(monitorsꢀvoltageꢀorꢀcurrent)ꢀorꢀGPI.
Internal temperature sensor.
14
15
16
17
ExternalꢀDS75LVꢀtemperatureꢀsensorꢀwithꢀI2Cꢀaddressꢀ90h.
ExternalꢀDS75LVꢀtemperatureꢀsensorꢀwithꢀI2C address 92h.
ExternalꢀDS75LVꢀtemperatureꢀsensorꢀwithꢀI2C address 94h.
ExternalꢀDS75LVꢀtemperatureꢀsensorꢀwithꢀI2C address 96h.
Reserved.
18
19
20
21–254
255
Applies to all pages.
*PAGES 0–11 can also be used to configure GPI and GPO operation.
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
all warnings and faults on the selected power supply are
ignored. Any command value not shown in these tables
is an invalid command. If the device receives a data
byte that is not listed in these tables, then it treats this
asꢀinvalidꢀdata,ꢀdeclaresꢀaꢀdataꢀfaultꢀ(setsꢀCMLꢀbitꢀandꢀ
asserts ALERT),ꢀandꢀrespondsꢀasꢀdescribedꢀinꢀtheꢀFault
Management and Reporting section.
OPERATION (01h)
Theꢀ OPERATIONꢀ commandꢀ isꢀ usedꢀ toꢀ turnꢀ theꢀ powerꢀ
supplyꢀ onꢀ andꢀ offꢀ inꢀ conjunctionꢀ withꢀ theꢀ CONTROLnꢀ
inputꢀ pin.ꢀ Theꢀ OPERATIONꢀ commandꢀ isꢀ alsoꢀ usedꢀ toꢀ
cause the power supply to set the output voltage to the
upper or lower margin voltages. The power supply stays
in the commanded operating mode until a subsequent
OPERATIONꢀ commandꢀ orꢀ aꢀ changeꢀ inꢀ theꢀ stateꢀ ofꢀ
theꢀ CONTROLnꢀ pinꢀ (ifꢀ enabled)ꢀ instructsꢀ theꢀ powerꢀ
supplyꢀtoꢀchangeꢀtoꢀanotherꢀstate.ꢀTheꢀvalidꢀOPERATIONꢀ
command byte values are shown in Tableꢀ 10. The
OPERATIONꢀcommandꢀcontrolsꢀhowꢀtheꢀdeviceꢀrespondsꢀ
whenꢀ commandedꢀ toꢀ changeꢀ theꢀ output.ꢀ Whenꢀ theꢀ
commandꢀbyteꢀisꢀ00h,ꢀtheꢀdeviceꢀimmediatelyꢀturnsꢀtheꢀ
power supply off and ignores any programmed turn-off
delay.ꢀWhenꢀtheꢀcommandꢀbyteꢀisꢀsetꢀtoꢀ40h,ꢀ41h,ꢀorꢀ42hꢀ
the device powers down, according to the programmed
turn-off delay. In Tableꢀ10, Table 11, and Table 12,ꢀ“actꢀ
onꢀ anyꢀ fault”ꢀ meansꢀ thatꢀ ifꢀ anyꢀ warningꢀ orꢀ faultꢀ onꢀ theꢀ
selected power supply is detected when the output is
margined, the device treats this as a warning or fault and
respondsꢀasꢀprogrammed.ꢀ“Ignoreꢀallꢀfaults”ꢀmeansꢀthatꢀ
In most cases, for power-on and power-off control, the
OPERATIONꢀcommandꢀshouldꢀbeꢀsentꢀwhenꢀtheꢀPAGEꢀ
isꢀsetꢀtoꢀ255.ꢀIfꢀtheꢀPAGEꢀisꢀsetꢀtoꢀ0–11,ꢀtheꢀOPERATIONꢀ
command is only applied to the power supply on that
page and the power supply is turned on and off using the
associatedꢀ TON_DELAYꢀ andꢀ TOFF_DELAYꢀ settingsꢀ
without any regard to the other supplies.
Forꢀindividualꢀchannel-marginingꢀcontrol,ꢀtheꢀOPERATIONꢀ
commandꢀcanꢀbeꢀusedꢀwithꢀtheꢀPAGEꢀsetꢀtoꢀ0–11.ꢀWhenꢀ
theꢀ PAGEꢀ isꢀ setꢀ toꢀ 255,ꢀ theꢀ OPERATIONꢀ marginingꢀ
commands affect all channels.
TheꢀOPERATIONꢀcommandꢀforꢀtheꢀdeviceꢀcontainsꢀaꢀfewꢀ
specialꢀvaluesꢀthatꢀareꢀnotꢀpartꢀofꢀtheꢀPMBusꢀstandardꢀ
toꢀallowꢀtheꢀdeviceꢀtoꢀofferꢀindependentꢀcontrol.ꢀSeeꢀtheꢀ
shaded values in Table 11.
Table 10. OPERATION (01h) Command Byte with PAGE = 0–11
(When Bit 3 of ON_OFF_CONFIG = 1)
COMMAND BYTE
POWER SUPPLY ON/OFF
MARGIN STATE
—
00h
40h
80h
94h
98h
A4h
A8h
Immediateꢀoffꢀ(noꢀsequencing)
Soft-offꢀ(withꢀsequencing)
—
On
On
On
On
On
Marginꢀoff
Marginꢀlowꢀ(ignoreꢀallꢀfaults)
Marginꢀlowꢀ(actꢀonꢀanyꢀfault)
Marginꢀhighꢀ(ignoreꢀallꢀfaults)
Marginꢀhighꢀ(actꢀonꢀanyꢀfault)
Note: All enabled channels must exceed POWER_GOOD_ON for margining to begin.
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Table 11. OPERATION (01h) Command Byte with PAGE = 255
(When Bit 3 of ON_OFF_CONFIG = 1)
COMMAND BYTE
POWER SUPPLY ON/OFF
SEQUENCE AFFECTED
MARGIN STATE
SEQUENCE0ꢀandꢀ
SEQUENCE1
00h
Immediateꢀoff
(noꢀsequencing)
01h
02h
SEQUENCE0ꢀonly
SEQUENCE1ꢀonly
n/a
SEQUENCE0ꢀandꢀ
SEQUENCE1
40h
Soft-off
(withꢀsequencing)
41h
42h
SEQUENCE0ꢀonly
SEQUENCE1ꢀonly
SEQUENCE0ꢀandꢀ
SEQUENCE1
80h
On
Marginꢀoff
81h
82h
94h
98h
A4h
A8h
SEQUENCE0ꢀonly
SEQUENCE1ꢀonly
On
On
On
On
Marginꢀlowꢀ(ignoreꢀallꢀfaults)
Marginꢀlowꢀ(actꢀonꢀanyꢀfault)
Marginꢀhighꢀ(ignoreꢀallꢀfaults)
Marginꢀhighꢀ(actꢀonꢀanyꢀfault)
SEQUENCE0ꢀandꢀ
SEQUENCE1
Note: Special device OPERATION commands are shaded; when the OPERATION command is read, the device always responds
with the standard command; all enabled channels must exceed POWER_GOOD_ON for margining to begin.
Table 12. OPERATION (01h) Command Byte
(When Bit 3 of ON_OFF_CONFIG = 0)
POWER SUPPLY
COMMAND BYTE
MARGIN STATE
ON/OFF
00h
40h
80h
94h
98h
A4h
A8h
n/a
Marginꢀoff
Commandꢀhasꢀnoꢀeffect
Marginꢀlowꢀ(ignoreꢀallꢀfaults)
Marginꢀlowꢀ(actꢀonꢀanyꢀfault)
Marginꢀhighꢀ(ignoreꢀallꢀfaults)
Marginꢀhighꢀ(actꢀonꢀanyꢀfault)
Note: The device only takes action if the supply is enabled; all enabled channels must exceed POWER_GOOD_ON for margining to
begin; if PAGE is set to 255, both SEQUENCE0 and SEQUENCE1 are affected.
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
edꢀ whenꢀ powerꢀ isꢀ applied.ꢀ Theꢀ ON_OFF_CONFIGꢀ
message content is described in Table 13. The host should
notꢀ modifyꢀ ON_OFF_CONFIGꢀ whileꢀ theꢀ powerꢀ suppliesꢀ
areꢀ active.ꢀ Theꢀ configurationꢀ ofꢀ theꢀ ON_OFF_CONFIGꢀ
commandꢀ appliesꢀ toꢀ bothꢀ CONTROL0ꢀ andꢀ CONTROL1.
SeeꢀFigureꢀ5.
ON_OFF_CONFIG (02h)
TheꢀON_OFF_CONFIGꢀcommandꢀconfiguresꢀtheꢀcombina-
tionꢀ ofꢀ theꢀ CONTROLnꢀ inputꢀ andꢀ PMBusꢀ OPERATIONꢀ
commands needed to turn the power supply on and
off. This indicates how the power supply is command-
Table 13. ON_OFF_CONFIG (02h) Command Byte
BIT
PURPOSE
VALUE
MEANING
7:6
Reserved.
n/a
0
Alwaysꢀreturnsꢀ000.
OPERATIONꢀcommandꢀisꢀANDedꢀwithꢀCONTROLnꢀpinꢀifꢀbothꢀareꢀenabled.
OPERATIONꢀcommandꢀisꢀORedꢀwithꢀCONTROLnꢀpinꢀifꢀbothꢀareꢀenabled.
OPERATIONꢀcommandꢀandꢀ
CONTROLnꢀpinꢀand/orꢀselect.
5
4
1
Turnsꢀonꢀtheꢀsuppliesꢀ(withꢀsequencingꢀifꢀsoꢀconfigured)ꢀasꢀsoonꢀasꢀbiasꢀisꢀ
suppliedꢀtoꢀtheꢀdevice,ꢀregardlessꢀofꢀtheꢀCONTROLnꢀpin.
0
Turn on supplies when bias is
presentꢀorꢀuseꢀtheꢀCONTROLnꢀ
pin/OPERATIONꢀcommand.
UsesꢀCONTROLnꢀpinsꢀ(ifꢀenabled)ꢀand/orꢀOPERATIONꢀcommand
(ifꢀenabled).*
1
0
1
0
1
0
1
0
1
On/offꢀportionꢀofꢀtheꢀOPERATIONꢀcommandꢀdisabled.
OPERATIONꢀcommandꢀenabled.
3
2
1
0
OPERATIONꢀcommandꢀenable.
CONTROLnꢀpinꢀenable.
CONTROLnꢀpinꢀdisabled.
CONTROLnꢀpinꢀenabled.
Activeꢀlowꢀ(driveꢀlowꢀtoꢀturnꢀonꢀtheꢀpowerꢀsupplies).
Activeꢀhighꢀ(driveꢀhighꢀtoꢀturnꢀonꢀtheꢀpowerꢀsupplies).
Usesꢀtheꢀprogrammedꢀturn-offꢀdelayꢀ(soft-off).
Turnsꢀoffꢀtheꢀpowerꢀsuppliesꢀimmediately.
CONTROLnꢀpinꢀpolarity.
CONTROLnꢀpinꢀturn-offꢀaction.
*Unless bit 5 is set (if both bits 3:2 are set), both the CONTROL0 or CONTROL1 pin and the OPERATION command are required to
turn the supplies on, and either can turn the supplies off.
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
DEVICE
POWER-ON
80h/40h/00h or 81h/41h/01h
OPERATION
COMMAND
0
AND
0
SEQUENCE0
AND
OR
SELECT
1
SELECT
1
CONTROL0 PIN
XOR
AND
AND
OR
ON_OFF_CONFIG
BIT 1
BIT 3 BIT 2
BIT 5
BIT 4
OR
AND
AND
1
0
XOR
OR
CONTROL1 PIN
1
0
SELECT
SEQUENCE1
SELECT
AND
AND
80h/40h/00h or 82h/42h/02h
NOTE: SIGNALS LISTED IN ITALICS ARE INTERNAL SIGNALS THAT CONNECT TO OTHER DEVICE FUNCTIONS.
SHADED BLOCKS ARE PMBus COMMANDS.
Figure 5. ON_OFF_CONFIG Logical Control
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
The device stores configuration data in both nonvolatile
flashꢀ memoryꢀ andꢀ volatileꢀ RAM.ꢀ Theꢀ PMBusꢀ engineꢀ
managesꢀtheꢀdeviceꢀconfigurationꢀdata.ꢀSeeꢀFigureꢀ6.
CLEAR_FAULTS (03h)
Theꢀ CLEAR_FAULTSꢀ commandꢀ isꢀ usedꢀ toꢀ clearꢀ anyꢀ
latched fault or warning bits in the status registers that have
been set and also unconditionally deasserts the ALERT
output. This command clears all bits simultaneously. It
alsoꢀ clearsꢀ theꢀ PORꢀ andꢀ WATCHDOG_INTꢀ bitsꢀ inꢀ theꢀ
STATUS_MFR_SPECIFICꢀregister.ꢀTheꢀCLEAR_FAULTSꢀ
command does not cause a power supply that has latched
offꢀforꢀaꢀfaultꢀconditionꢀtoꢀrestart.ꢀTheꢀstateꢀofꢀtheꢀPSENnꢀ
outputs under fault conditions are not affected by this
command and changes only if commanded through the
OPERATIONꢀ commandꢀ orꢀ theꢀ CONTROLnꢀ pins.ꢀ Ifꢀ aꢀ
faultꢀisꢀstillꢀpresentꢀafterꢀtheꢀCLEAR_FAULTSꢀcommandꢀisꢀ
executed, the fault status bit is immediately set again, but
ALERT is not reasserted. ALERT is only asserted again
when a new fault or warning is detected that occurs after the
CLEAR_FAULTSꢀcommandꢀisꢀexecuted.ꢀThisꢀcommandꢀisꢀ
write-only. There is no data byte for this command.
The flash memory has three separate arrays for
configurationꢀparameters,ꢀwhereasꢀtheꢀRAMꢀonlyꢀhasꢀaꢀ
singleꢀarray.ꢀWhenꢀaꢀPMBusꢀcommandꢀisꢀwrittenꢀtoꢀtheꢀ
device,ꢀitꢀisꢀalwaysꢀwrittenꢀtoꢀtheꢀRAM.ꢀWhenꢀtheꢀdeviceꢀ
isꢀ shippedꢀ fromꢀ theꢀ factory,ꢀ theꢀ MAINꢀ andꢀ BACKUPꢀ
flash memory arrays are identical and are configured as
shown in Table 3. TheꢀSINGLEꢀarrayꢀisꢀempty.
ThereꢀisꢀaꢀsetꢀofꢀfiveꢀPMBusꢀcommandsꢀthatꢀcanꢀbeꢀusedꢀ
toꢀtransferꢀdataꢀbetweenꢀtheꢀflashꢀandꢀRAMꢀarrays.ꢀTheseꢀ
commands are described in Table 15.
FLASH
CONFIGURATION
RAM
MAIN
WRITE_PROTECT (10h)
CONFIGURATION
PMBus
Theꢀ WRITE_PROTECTꢀ commandꢀ isꢀ usedꢀ toꢀ provideꢀ
protection against accidental changes to the device’s oper-
ating memory. All supported commands can have their
parametersꢀ read,ꢀ regardlessꢀ ofꢀ theꢀ WRITE_PROTECTꢀ
settings.ꢀ Theꢀ WRITE_PROTECTꢀ messageꢀ contentꢀ isꢀ
described in Table 14.
CONTROL AND
MONITORING
ENGINE
OPERATING
BACKUP
SINGLE
Figure 6. Device Configuration Data Management
Device Configuration Data Management
Table 14. WRITE_PROTECT (10h) Command Byte
COMMAND BYTE
MEANING
DisablesꢀallꢀwritesꢀexceptꢀtheꢀWRITE_PROTECTꢀcommand.
DisablesꢀallꢀwritesꢀexceptꢀtheꢀWRITE_PROTECT,ꢀOPERATION,ꢀandꢀPAGEꢀcommands.
80h
40h
DisablesꢀallꢀwritesꢀexceptꢀtheꢀWRITE_PROTECT,ꢀOPERATION,ꢀPAGE,ꢀandꢀON_OFF_CONFIGꢀ
commands.
20h
00h
Enablesꢀwritesꢀforꢀallꢀcommandsꢀ(default).
Note: No fault or error is generated if the host attempts to write to a protected area.
Table 15. Memory Transfer PMBus Commands
PMBus COMMAND
STORE_DEFAULT_ALL
RESULTING MEMORY TRANSFER
CopiesꢀRAMꢀOPERATINGꢀtoꢀtheꢀflashꢀMAIN.
RESTORE_DEFAULT_ALL
CopiesꢀtheꢀflashꢀMAINꢀtoꢀRAMꢀOPERATING.
CODEꢀ=ꢀ00h
CODEꢀ=ꢀ01h
CODEꢀ=ꢀ00h
CODEꢀ=ꢀ01h
CopiesꢀRAMꢀOPERATINGꢀtoꢀtheꢀflashꢀMAIN.
MFR_STORE_ALL
CopiesꢀRAMꢀOPERATINGꢀtoꢀtheꢀflashꢀBACKUP.
CopiesꢀtheꢀflashꢀMAINꢀarrayꢀtoꢀRAMꢀOPERATING.
CopiesꢀtheꢀflashꢀBACKUPꢀtoꢀRAMꢀOPERATING.
CopiesꢀRAMꢀOPERATINGꢀ(singleꢀparameter)ꢀtoꢀtheꢀflashꢀSINGLE.
MFR_RESTORE_ALL
MFR_STORE_SINGLE
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
AllꢀotherꢀCODEꢀvaluesꢀareꢀignored.ꢀNotꢀallꢀinformationꢀisꢀ
stored. Only configuration data is stored, not any status
or operational data. If an error occurs during the transfer,
ALERTꢀassertsꢀifꢀenabledꢀandꢀtheꢀCMLꢀbitꢀinꢀSTATUS_
WORDꢀisꢀsetꢀtoꢀ1.ꢀNoꢀbitsꢀareꢀsetꢀinꢀSTATUS_CML.ꢀNoteꢀ
thatꢀifꢀtheꢀCODEꢀisꢀ00h,ꢀthenꢀthisꢀcommandꢀoperatesꢀtheꢀ
sameꢀasꢀSTORE_DEFAULT_ALL.
STORE_DEFAULT_ALL (11h)
TheꢀSTORE_DEFAULT_ALLꢀcommandꢀinstructsꢀtheꢀdeviceꢀ
toꢀ copyꢀ RAMꢀ OPERATINGꢀ toꢀ theꢀ flashꢀ MAINꢀ memoryꢀ
array.ꢀNotꢀallꢀinformationꢀisꢀstored.ꢀOnlyꢀconfigurationꢀdataꢀ
is stored, not any status or operational data. If an error
occurs during the transfer, ALERT asserts if enabled and
theꢀCMLꢀbitꢀinꢀSTATUS_WORDꢀisꢀsetꢀtoꢀ1.ꢀNoꢀbitsꢀareꢀsetꢀ
inꢀSTATUS_CML.ꢀThisꢀcommandꢀisꢀwrite-only.ꢀThereꢀisꢀnoꢀ
data byte for this command.
CopyꢀRAMꢀOPERATINGꢀtoꢀflashꢀMAIN
CopyꢀRAMꢀOPERATINGꢀtoꢀflashꢀBACKUP
CODEꢀ=ꢀ00h
CODEꢀ=ꢀ01h
WhenꢀtheꢀSTORE_DEFAULT_ALLꢀcommandꢀisꢀinvoked,ꢀ
theꢀ deviceꢀ isꢀ unresponsiveꢀ toꢀ PMBusꢀ commandsꢀ andꢀ
does not monitor power supplies while transferring the
configuration. The time required to complete this task
is listed in the Electrical Characteristics section. The
MFR_STORE_SINGLEꢀ commandꢀ allowsꢀ aꢀ singleꢀ
command to be stored in much less time.
Whenꢀ theꢀ MFR_STORE_ALLꢀ commandꢀ isꢀ invoked,ꢀ
theꢀ deviceꢀ isꢀ unresponsiveꢀ toꢀ PMBusꢀ commandsꢀ andꢀ
does not monitor power supplies while transferring the
configuration. The time required to complete this task
is listed in the Electrical Characteristics section. The
MFR_STORE_SINGLEꢀ commandꢀ allowsꢀ aꢀ singleꢀ
command to be stored in much less time.
USER NOTE: V
must be above 2.9V for the device to
DD
performꢀtheꢀSTORE_DEFAULT_ALLꢀcommand.
USER NOTE: V
must be above 2.9V for the device to
DD
RESTORE_DEFAULT_ALL (12h)
performꢀtheꢀMFR_STORE_ALLꢀcommand.
Theꢀ RESTORE_DEFAULT_ALLꢀ commandꢀ instructsꢀ theꢀ
deviceꢀ toꢀ copyꢀ theꢀ flashꢀ MAINꢀ memoryꢀ arrayꢀ toꢀ RAMꢀ
OPERATING.ꢀTheꢀRESTORE_DEFAULT_ALLꢀcommandꢀ
should only be executed when the device is not operating
the power supplies. This command is write-only. There
isꢀ noꢀ dataꢀ byteꢀ forꢀ thisꢀ command.ꢀ Whenꢀ RESTORE_
DEFAULT_ALLꢀisꢀissued,ꢀtheꢀdataꢀisꢀcheckedꢀforꢀvalidityꢀ
beforeꢀbeingꢀtransferred.ꢀIfꢀtheꢀMAINꢀarrayꢀisꢀcorrupt,ꢀtheꢀ
deviceꢀsetsꢀbitꢀ1ꢀofꢀSTATUS_CMLꢀandꢀloadsꢀtheꢀBACKUPꢀ
copy.ꢀ Ifꢀ theꢀ BACKUPꢀ copyꢀ isꢀ corrupt,ꢀ thenꢀ theꢀ deviceꢀ
setsꢀ bitꢀ 2ꢀ ofꢀ STATUS_CMLꢀ andꢀ remainsꢀ inꢀ aꢀ nullꢀ stateꢀ
withꢀallꢀpinsꢀ(exceptꢀSCLꢀandꢀSDA)ꢀinꢀhighꢀimpedance.ꢀ
The FAULTnꢀ pin(s)ꢀ areꢀ alsoꢀ asserted.ꢀ Toꢀ resolveꢀ theꢀ
data corruption, the configuration data must be written to
RAMꢀOPERATINGꢀandꢀSTORE_DEFAULT_ALLꢀmustꢀbeꢀ
issued, followed by a device reset.
MFR_RESTORE_ALL (EFh)
TheꢀMFR_RESTORE_ALLꢀcommandꢀinstructsꢀtheꢀdeviceꢀ
toꢀ copyꢀ eitherꢀ theꢀ flashꢀ MAINꢀ memoryꢀ arrayꢀ (CODEꢀ =ꢀ
00h)ꢀorꢀtheꢀflashꢀBACKUPꢀmemoryꢀarrayꢀ(CODEꢀ=ꢀ01h)ꢀ
toꢀRAMꢀOPERATING.ꢀThisꢀcommandꢀisꢀwrite-only.ꢀThereꢀ
isꢀ 1ꢀ dataꢀ byteꢀ forꢀ thisꢀ command,ꢀ whichꢀ isꢀ theꢀ CODE.ꢀ
Theꢀ CODEꢀ isꢀ eitherꢀ 00hꢀ toꢀ instructꢀ theꢀ deviceꢀ toꢀ copyꢀ
fromꢀtheꢀMAINꢀarrayꢀorꢀ01hꢀtoꢀcopyꢀfromꢀtheꢀBACKUPꢀ
array.ꢀAllꢀotherꢀCODEꢀvaluesꢀareꢀignored.ꢀNoteꢀthatꢀifꢀtheꢀ
CODEꢀisꢀ00h,ꢀthenꢀthisꢀcommandꢀoperatesꢀtheꢀsameꢀasꢀ
RESTORE_DEFAULT_ALL.
CopyꢀflashꢀMAINꢀtoꢀRAMꢀOPERATING
CopyꢀflashꢀBACKUPꢀtoꢀRAMꢀOPERATING
CODEꢀ=ꢀ00h
CODEꢀ=ꢀ01h
Theꢀ MFR_RESTORE_ALLꢀ commandꢀ shouldꢀ onlyꢀ beꢀ
executed when the device is not operating the power
supplies.
Uponꢀaꢀdeviceꢀpower-onꢀreset,ꢀorꢀanyꢀdeviceꢀreset,ꢀthisꢀ
command is automatically executed by the device without
PMBusꢀactionꢀrequired.
WhenꢀMFR_RESTORE_ALLꢀisꢀissued,ꢀtheꢀdataꢀisꢀcheckedꢀ
forꢀ validityꢀ beforeꢀ beingꢀ transferred.ꢀ Ifꢀ theꢀ MAINꢀ arrayꢀ
isꢀ corrupt,ꢀ theꢀ deviceꢀ setsꢀ bitꢀ 1ꢀ ofꢀ STATUS_CML.ꢀ Ifꢀ theꢀ
BACKUPꢀ arrayꢀ isꢀ corrupt,ꢀ thenꢀ theꢀ deviceꢀ setsꢀ bitꢀ 2ꢀ ofꢀ
STATUS_CML.ꢀNoꢀotherꢀactionꢀisꢀtakenꢀbyꢀtheꢀdevice.ꢀToꢀ
resolve the data corruption, the configuration data must be
writtenꢀtoꢀRAMꢀOPERATINGꢀandꢀSTORE_DEFAULT_ALLꢀ
orꢀMFR_STORE_ALLꢀmustꢀbeꢀissued.
MFR_STORE_ALL (EEh)
TheꢀMFR_STORE_ALLꢀcommandꢀinstructsꢀtheꢀdeviceꢀtoꢀ
copyꢀRAMꢀOPERATINGꢀtoꢀeitherꢀtheꢀflashꢀMAINꢀmemoryꢀ
arrayꢀ(CODEꢀ=ꢀ00h)ꢀorꢀtheꢀflashꢀBACKUPꢀmemoryꢀarrayꢀ
(CODEꢀ =ꢀ 01h).ꢀThisꢀ commandꢀ isꢀ write-only.ꢀThereꢀ isꢀ 1ꢀ
dataꢀ byteꢀ forꢀ thisꢀ command,ꢀ whichꢀ isꢀ theꢀ CODE.ꢀ Theꢀ
CODEꢀ isꢀ eitherꢀ 00hꢀ toꢀ instructꢀ theꢀ deviceꢀ toꢀ copyꢀ intoꢀ
theꢀMAINꢀarray,ꢀorꢀ01hꢀtoꢀcopyꢀintoꢀtheꢀBACKUPꢀarray.ꢀ
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
USER NOTE: V
performꢀtheꢀMFR_STORE_SINGLEꢀcommand.
must be above 2.9V for the device to
MFR_STORE_SINGLE (FCh)
DD
MFR_STORE_SINGLEꢀ isꢀ aꢀ read/writeꢀ wordꢀ commandꢀ
that instructs the device to transfer a single configuration
parameterꢀfromꢀRAMꢀOPERATINGꢀtoꢀtheꢀflashꢀSINGLEꢀ
memoryꢀarray.ꢀTheꢀupperꢀbyteꢀcontainsꢀtheꢀPAGEꢀandꢀtheꢀ
lowerꢀbyteꢀcontainsꢀtheꢀPMBusꢀcommandꢀthatꢀshouldꢀbeꢀ
stored.ꢀForꢀexample,ꢀifꢀtheꢀTON_DELAYꢀparameterꢀforꢀtheꢀ
powerꢀsupplyꢀcontrolledꢀbyꢀPAGEꢀ4ꢀneedsꢀtoꢀbeꢀstoredꢀ
toꢀ flash,ꢀ 0460hꢀ wouldꢀ beꢀ writtenꢀ withꢀ thisꢀ command.ꢀ
Whenꢀread,ꢀthisꢀcommandꢀreportsꢀtheꢀlastꢀsingleꢀPAGE/
command written to flash. This command can be used
while the device is operating the power supplies. If an
error occurs during the transfer, ALERT asserts if enabled
andꢀtheꢀCMLꢀbitꢀinꢀSTATUS_WORDꢀisꢀsetꢀtoꢀ1.ꢀNoꢀbitsꢀ
areꢀ setꢀ inꢀ STATUS_CML.ꢀ Theꢀ MFR_STORE_SINGLEꢀ
commandꢀ shouldꢀ onlyꢀ beꢀ invokedꢀ aꢀ maximumꢀ ofꢀ 85ꢀ
times before either a device reset is issued or a device
powerꢀ cycleꢀ occurs,ꢀ orꢀ theꢀ RESTORE_DEFAULT_ALLꢀ
commandꢀ isꢀ invoked.ꢀ Onceꢀ theꢀ MFR_STORE_SINGLEꢀ
commandꢀ isꢀ invoked,ꢀ theꢀ STORE_DEFAULT_ALLꢀ andꢀ
MFR_STORE_ALLꢀ commandsꢀ shouldꢀ notꢀ beꢀ usedꢀ untilꢀ
either a device reset is issued or a device power cycle
occurs,ꢀ orꢀ theꢀ RESTORE_DEFAULT_ALLꢀ commandꢀ isꢀ
invoked.ꢀAlso,ꢀMFR_STORE_SINGLEꢀshouldꢀnotꢀbeꢀusedꢀ
forꢀcommandsꢀthatꢀareꢀnotꢀstoredꢀinꢀflash.ꢀSeeꢀTable 3 for
a list of commands that are stored in flash.
MFR_CRC (FEh)
MFR_CRCꢀisꢀaꢀread/writeꢀwordꢀcommandꢀthatꢀinstructsꢀ
theꢀ deviceꢀ toꢀ reportꢀ theꢀ calculatedꢀ 16-bitꢀ CRCꢀ valueꢀ
ofꢀ eitherꢀ theꢀ RAMꢀ OPERATINGꢀ orꢀ theꢀ flashꢀ MAINꢀ orꢀ
BACKUPꢀ memoryꢀ arrays.ꢀ Aꢀ CRCꢀ valueꢀ forꢀ theꢀ flashꢀ
SINGLEꢀ arrayꢀ isꢀ notꢀ available.ꢀ Onlyꢀ oneꢀ 16-bitꢀ CRCꢀ isꢀ
reportedꢀ withꢀ eachꢀ readꢀ ofꢀ MFR_CRC.ꢀTheꢀ CRCꢀ valueꢀ
to be reported is determined by the most previous
writtenꢀCODEꢀvalue,ꢀasꢀshownꢀinꢀTable 16.ꢀForꢀexample,ꢀ
ifꢀMFR_CRCꢀisꢀfirstꢀwrittenꢀwithꢀaꢀCODEꢀofꢀ0001h,ꢀthenꢀ
theꢀ nextꢀ readꢀ ofꢀ MFR_CRCꢀ reportsꢀ theꢀ CRCꢀ forꢀ theꢀ
flashꢀ BACKUPꢀ array.ꢀ Ifꢀ noꢀ CODEꢀ valueꢀ isꢀ written,ꢀ thanꢀ
MFR_CRCꢀreturnsꢀFFFFhꢀwhenꢀread.ꢀSeeꢀTable 16.
CAPABILITY (19h)
TheꢀCAPABILITYꢀcommandꢀisꢀusedꢀtoꢀdetermineꢀsomeꢀkeyꢀ
capabilitiesꢀ ofꢀ theꢀ device.ꢀTheꢀ CAPABILITYꢀ commandꢀ isꢀ
read-only. The message content is described in Table 17.
VOUT_MODE (20h)
TheꢀVOUT_MODEꢀcommandꢀisꢀusedꢀtoꢀreportꢀtheꢀdataꢀ
formatꢀofꢀtheꢀdevice.ꢀTheꢀdeviceꢀusesꢀtheꢀDIRECTꢀformatꢀ
for all the voltage-related commands. The value returned
isꢀ40h,ꢀindicatingꢀDIRECTꢀdataꢀformat.ꢀThisꢀcommandꢀisꢀ
read-only. If a host attempts to write this command, the
CMLꢀstatusꢀbitꢀisꢀasserted.ꢀSeeꢀTable 5 for the m, b, and
Rꢀvaluesꢀforꢀtheꢀvariousꢀcommands.
Table 16. MFR_CRC (FEh) Command Byte
MEMORY ARRAY CRC VALUE TO
MFR_CRC CODE
BE REPORTED ON NEXT READ
VALUE
VOUT_MARGIN_HIGH (25h)
OF MFR_CRC
Theꢀ VOUT_MARGIN_HIGHꢀ commandꢀ loadsꢀ theꢀ deviceꢀ
with the voltage to which the power-supply output is to
beꢀ changedꢀ whenꢀ theꢀ OPERATIONꢀ commandꢀ isꢀ setꢀ toꢀ
margin high. If the power supply is already operating at
0000h
0001h
0002h
FlashꢀMAIN
FlashꢀBACKUP
RAMꢀOPERATING
Table 17. CAPABILITY (19h) Command Byte
BIT
7
NAME
MEANING
Packet-errorꢀchecking
PMBusꢀspeed
0ꢀ=ꢀPECꢀnotꢀsupported.
6:5
01ꢀ=ꢀMaximumꢀsupportedꢀbusꢀspeedꢀisꢀ400kHz.
1ꢀ=ꢀDeviceꢀsupportsꢀanꢀALERTꢀoutputꢀ(ALERTꢀisꢀenabledꢀinꢀMFR_MODE).
0ꢀ=ꢀDeviceꢀdoesꢀnotꢀsupportꢀALERTꢀoutputꢀ(ALERTꢀisꢀdisabledꢀinꢀMFR_MODE).
4
ALERT
3:0
Reserved
Alwaysꢀreturnsꢀ0000.
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
marginꢀ high,ꢀ changingꢀ VOUT_MARGIN_HIGHꢀ hasꢀ noꢀ
effect on the output voltage. The device only adjusts
theꢀ powerꢀ supplyꢀ toꢀ theꢀ newꢀ VOUT_MARGIN_HIGHꢀ
voltageꢀ afterꢀ receivingꢀ aꢀ newꢀ margin-highꢀ OPERATIONꢀ
command.ꢀTheꢀ2ꢀdataꢀbytesꢀareꢀinꢀDIRECTꢀformat.ꢀIfꢀtheꢀ
device cannot successfully close-loop margin the power
supply, the device keeps attempting to margin the supply
andꢀdoesꢀtheꢀfollowing:
VOUT_SCALE_MONITOR (2Ah)
In applications where the measured power-supply volt-
ageꢀisꢀnotꢀequalꢀtoꢀtheꢀvoltageꢀatꢀtheꢀADCꢀinput,ꢀVOUT_
SCALE_MONITORꢀisꢀused.ꢀForꢀexample,ꢀifꢀtheꢀADCꢀinputꢀ
expectsꢀ aꢀ 1.8Vꢀ inputꢀ forꢀ aꢀ 12Vꢀ output,ꢀ VOUT_SCALE_
MONITORꢀ=ꢀ1.8V/12Vꢀ=ꢀ0.15.ꢀInꢀapplicationsꢀwhereꢀtheꢀ
power-supply output voltage is greater than the device
inputꢀ rangeꢀ ofꢀ 2.048V,ꢀ theꢀ outputꢀ voltageꢀ ofꢀ theꢀ powerꢀ
supply is sensed through a resistive voltage-divider. The
resistive voltage-divider reduces or scales the output
voltage.ꢀTheꢀPMBusꢀcommandsꢀspecifyꢀtheꢀactualꢀpower-
supply output voltages and not the input voltage to the
ADC.ꢀToꢀallowꢀtheꢀdeviceꢀtoꢀmapꢀbetweenꢀtheꢀhighꢀpower-
supplyꢀ voltagesꢀ (suchꢀ asꢀ 12V)ꢀ andꢀ theꢀ voltageꢀ atꢀ theꢀ
ADCꢀ input,ꢀ theꢀ VOUT_SCALE_MONITORꢀ commandꢀ isꢀ
used.ꢀTheꢀ2ꢀdataꢀbytesꢀareꢀinꢀDIRECTꢀformat.ꢀThisꢀvalueꢀ
is dimensionless. As an example, if the required scaling
factorꢀisꢀ0.15,ꢀthenꢀVOUT_SCALE_MONITORꢀshouldꢀbeꢀ
setꢀtoꢀ1333hꢀ(4915/32,767ꢀ=ꢀ0.15).ꢀSeeꢀTableꢀ18.
1)ꢀ SetsꢀtheꢀMARGINꢀbitꢀinꢀSTATUS_WORD.
2)ꢀ Setsꢀ theꢀ MARGIN_FAULTꢀ bitꢀ inꢀ STATUS_MFR_
SPECIFICꢀ(PAGESꢀ0–11).
3)ꢀ NotifiesꢀtheꢀhostꢀthroughꢀALERTꢀassertionꢀ(ifꢀenabledꢀ
inꢀMFR_MODE).
VOUT_MARGIN_LOW (26h)
Theꢀ VOUT_MARGIN_LOWꢀ commandꢀ loadsꢀ theꢀ deviceꢀ
with the voltage to which the power-supply output
changesꢀ toꢀ whenꢀ theꢀ OPERATIONꢀ commandꢀ isꢀ setꢀ toꢀ
margin low. If the power supply is already operating at
marginꢀ low,ꢀ changingꢀ VOUT_MARGIN_LOWꢀ hasꢀ noꢀ
effect on the output voltage. The device only adjusts the
powerꢀsupplyꢀtoꢀtheꢀnewꢀVOUT_MARGIN_LOWꢀvoltageꢀ
afterꢀreceivingꢀaꢀnewꢀmargin-lowꢀOPERATIONꢀcommand.ꢀ
Theꢀ 2ꢀ dataꢀ bytesꢀ areꢀ inꢀ DIRECTꢀ format.ꢀ Ifꢀ theꢀ deviceꢀ
cannot successfully close-loop margin the power supply,
the device keeps attempting to margin the supply and
doesꢀtheꢀfollowing:
IOUT_CAL_GAIN (38h)
TheꢀIOUT_CAL_GAINꢀcommandꢀisꢀusedꢀtoꢀsetꢀtheꢀratioꢀ
ofꢀ theꢀ voltageꢀ atꢀ theꢀADCꢀ inputꢀ toꢀ theꢀ sensedꢀ current.ꢀ
TheꢀunitsꢀofꢀtheꢀIOUT_CAL_GAINꢀfactorꢀareꢀ0.1mΩ.ꢀTheꢀ
2ꢀdataꢀbytesꢀareꢀinꢀDIRECTꢀformat.ꢀAsꢀanꢀexample,ꢀifꢀaꢀ
10mΩꢀsenseꢀresistorꢀisꢀusedꢀinꢀconjunctionꢀwithꢀaꢀ50V/Vꢀ
current-senseꢀamplifier,ꢀtheꢀIOUT_CAL_GAINꢀshouldꢀbeꢀ
setꢀtoꢀ500mΩꢀorꢀ1388h.
1)ꢀ SetsꢀtheꢀMARGINꢀbitꢀinꢀSTATUS_WORD
USER NOTE:ꢀTheꢀfull-scaleꢀADCꢀvoltageꢀonꢀtheꢀdeviceꢀ
isꢀ 2.048V.ꢀTheꢀ valueꢀ ofꢀ theꢀ senseꢀ resistorꢀ andꢀ current-
sense amplifier gain must be scaled appropriately. Also,
theꢀ maximumꢀ voltageꢀ atꢀ theꢀ RSnꢀ inputsꢀ mustꢀ beꢀ lessꢀ
than 4V. The maximum output impedance of the current-
senseꢀamplifierꢀisꢀlimitedꢀbyꢀtheꢀsettingꢀofꢀtheꢀADC_TIMEꢀ
bitsꢀ inꢀ MFR_MODE.ꢀ Seeꢀ theꢀ Recommended Operating
Conditions section for details.
2)ꢀ Setsꢀ theꢀ MARGIN_FAULTꢀ bitꢀ inꢀ STATUS_MFR_
SPECIFICꢀ(PAGESꢀ0–11)
3)ꢀ NotifiesꢀtheꢀhostꢀthroughꢀALERTꢀassertionꢀ(ifꢀenabledꢀ
inꢀMFR_MODE).
Table 18. VOUT_SCALE_MONITOR (2Ah) Examples
NOMINAL VOLTAGE LEVEL
MONITORED
NOMINAL ADC INPUT
VOLTAGE LEVEL*
RESISTIVE DIVIDER
RATIO
VOUT_SCALE_MONITOR
VALUE
1.8Vꢀorꢀless
2.5V
1.8V
1.8V
1.8V
1.8V
1.8V
1.0
0.72
7FFFh
5C28h
45D1h
2E14h
1333h
3.3V
0.545454
0.36
5V
12V
0.15
*The full-scale ADC voltage on the device is 2.048V. A scaling factor where a 1.8V ADC input represents a nominal 100%
voltage level is recommended to allow headroom for margining. Resistor-dividers must be used to measure voltage greater than
1.8V. The maximum source impedance of the resistor-divider is limited by the setting of the ADC_TIME bits in MFR_MODE.
See the RecommendedꢀOperatingꢀConditions section for details.
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
VOUT_OV_FAULT_LIMIT (40h)
VOUT_UV_FAULT_LIMIT (44h)
Theꢀ VOUT_OV_FAULT_LIMITꢀ commandꢀ setsꢀ theꢀ
value of the output voltage that causes an output
overvoltage fault. The monitored voltage must drop
by at least 2% below the limit before the fault is
allowedꢀ toꢀ clear.ꢀ Theꢀ 2ꢀ dataꢀ bytesꢀ areꢀ inꢀ DIRECTꢀ
format.ꢀ Inꢀ responseꢀ toꢀ theꢀ VOUT_OV_FAULT_LIMITꢀ
beingꢀexceeded,ꢀtheꢀdeviceꢀdoesꢀtheꢀfollowing:
Theꢀ VOUT_UV_FAULT_LIMITꢀ commandꢀ setsꢀ theꢀ valueꢀ
of the output voltage that causes an output undervoltage
fault. The monitored voltage must increase by at least 2%
above the limit before the fault is allowed to clear. This
fault is masked until the output voltage reaches the pro-
grammedꢀPOWER_GOOD_ONꢀforꢀtheꢀfirstꢀtimeꢀandꢀalsoꢀ
during turn-off when the power supply is disabled. If voltage
is being monitored, this should be set to a value greater
thanꢀ 100mV.ꢀTheꢀ 2ꢀ dataꢀ bytesꢀ areꢀ inꢀ DIRECTꢀ format.ꢀ Inꢀ
responseꢀtoꢀviolationꢀofꢀtheꢀVOUT_UV_FAULT_LIMIT,ꢀtheꢀ
deviceꢀdoesꢀtheꢀfollowing:
1)ꢀ SetsꢀtheꢀVOUT_OVꢀbitꢀandꢀtheꢀVOUTꢀbitꢀinꢀSTATUS_WORD.
2)ꢀ SetsꢀtheꢀVOUT_OV_FAULTꢀbitꢀinꢀSTATUS_VOUT.
3)ꢀ RespondsꢀasꢀspecifiedꢀinꢀtheꢀMFR_FAULT_RESPONSE.
4)ꢀ NotifiesꢀtheꢀhostꢀthroughꢀALERTꢀassertionꢀ(ifꢀenabledꢀ
1)ꢀ SetsꢀtheꢀVOUTꢀbitꢀinꢀSTATUS_WORD.
inꢀMFR_MODE).
2)ꢀ SetsꢀtheꢀVOUT_UV_FAULTꢀbitꢀinꢀSTATUS_VOUT.
3)ꢀ RespondsꢀasꢀspecifiedꢀinꢀMFR_FAULT_RESPONSE.
VOUT_OV_WARN_LIMIT (42h)
Theꢀ VOUT_OV_WARN_LIMITꢀ commandꢀ setsꢀ theꢀ valueꢀ
of the output voltage that causes an output-voltage high
warning. The monitored voltage must drop by at least 2%
below the limit before the warning is allowed to clear. This
value is typically less than the output overvoltage thresh-
oldꢀinꢀVOUT_OV_FAULT_LIMIT.ꢀTheꢀ2ꢀdataꢀbytesꢀareꢀinꢀ
DIRECTꢀformat.ꢀInꢀresponseꢀtoꢀtheꢀVOUT_OV_WARN_
LIMITꢀbeingꢀexceeded,ꢀtheꢀdeviceꢀdoesꢀtheꢀfollowing:
4)ꢀ NotifiesꢀtheꢀhostꢀusingꢀALERTꢀassertionꢀ(ifꢀenabledꢀinꢀ
MFR_MODE).
IOUT_OC_WARN_LIMIT (46h)
Theꢀ IOUT_OC_WARN_LIMITꢀ commandꢀ setsꢀ theꢀ valueꢀ
of the current that causes an overcurrent warning.
The monitored current must decrease by at least 5%
below the limit before the warning is allowed to clear.
This value is typically less than the overcurrent-fault
thresholdꢀ inꢀ IOUT_OC_FAULT_LIMIT.ꢀTheꢀ 2ꢀ dataꢀ bytesꢀ
areꢀ inꢀ DIRECTꢀ format.ꢀ Inꢀ responseꢀ toꢀ violationꢀ ofꢀ theꢀ
IOUT_OC_WARN_LIMIT,ꢀtheꢀdeviceꢀdoesꢀtheꢀfollowing:
1)ꢀ SetsꢀtheꢀVOUTꢀbitꢀinꢀSTATUS_WORD.
2)ꢀ SetsꢀtheꢀVOUT_OV_WARNꢀbitꢀinꢀSTATUS_VOUT.
3)ꢀ NotifiesꢀtheꢀhostꢀusingꢀALERTꢀassertionꢀ(ifꢀenabledꢀinꢀ
MFR_MODE).
1)ꢀ SetsꢀtheꢀIOUTꢀbitꢀinꢀSTATUS_WORD.
2)ꢀ SetsꢀtheꢀIOUT_OC_WARNꢀbitꢀinꢀSTATUS_IOUT.
VOUT_UV_WARN_LIMIT (43h)
3)ꢀ NotifiesꢀtheꢀhostꢀusingꢀALERTꢀassertionꢀ(ifꢀenabledꢀinꢀ
TheꢀVOUT_UV_WARN_LIMITꢀcommandꢀsetsꢀtheꢀvalueꢀofꢀ
the output voltage that causes an output-voltage low warn-
ing. The monitored voltage must increase by at least 2%
above the limit before the warning is allowed to clear. This
value is typically greater than the output undervoltage-fault
thresholdꢀ inꢀ VOUT_UV_FAULT_LIMIT.ꢀ Thisꢀ warningꢀ isꢀ
masked until the output voltage reaches the programmed
POWER_GOOD_ONꢀ forꢀ theꢀ firstꢀ timeꢀ andꢀ alsoꢀ duringꢀ
turn-off when the power supply is disabled. If voltage is
being monitored, this should be set to a value greater
thanꢀ100mV.ꢀTheꢀ2ꢀdataꢀbytesꢀareꢀinꢀDIRECTꢀformat.ꢀInꢀ
responseꢀtoꢀviolationꢀofꢀtheꢀVOUT_UV_WARN_LIMIT,ꢀtheꢀ
deviceꢀdoesꢀtheꢀfollowing:
MFR_MODE).
IOUT_OC_FAULT_LIMIT (4Ah)
Theꢀ IOUT_OC_FAULT_LIMITꢀ commandꢀ setsꢀ theꢀ valueꢀ
of the current that causes an overcurrent fault. The
monitored current must decrease by at least 5% below
the limit before the fault is allowed to clear. This fault is
masked until the current is below this limit for the first
time.ꢀTheꢀ2ꢀdataꢀbytesꢀareꢀinꢀDIRECTꢀformat.ꢀInꢀresponseꢀ
toꢀ violationꢀ ofꢀ theꢀ IOUT_OC_FAULT_LIMIT,ꢀ theꢀ deviceꢀ
doesꢀtheꢀfollowing:
1)ꢀ SetsꢀtheꢀIOUTꢀbitꢀinꢀSTATUS_WORD.
1)ꢀ SetsꢀtheꢀVOUTꢀbitꢀinꢀSTATUS_WORD.
2)ꢀ SetsꢀtheꢀIOUT_OC_FAULTꢀbitꢀinꢀSTATUS_IOUT.
2)ꢀ SetsꢀtheꢀVOUT_UV_WARNꢀbitꢀinꢀSTATUS_VOUT.
3)ꢀ Respondsꢀ asꢀ specifiedꢀ inꢀ theꢀ MFR_FAULT_
RESPONSE.
3)ꢀ NotifiesꢀtheꢀhostꢀusingꢀALERTꢀassertionꢀ(ifꢀenabledꢀinꢀ
MFR_MODE).
4)ꢀ NotifiesꢀtheꢀhostꢀusingꢀALERTꢀassertionꢀ(ifꢀenabledꢀinꢀ
MFR_MODE).
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
OT_FAULT_LIMIT (4Fh)
POWER_GOOD_OFF (5Fh)
Theꢀ OT_FAULT_LIMITꢀ commandꢀ setsꢀ theꢀ temperature,ꢀ
in degrees Celsius, of the selected temperature sensor
at which an overtemperature fault is detected. The moni-
toredꢀ temperatureꢀ mustꢀ dropꢀ byꢀ atꢀ leastꢀ 4°Cꢀ belowꢀ theꢀ
limit before the fault is allowed to clear. The 2 data bytes
areꢀ inꢀ DIRECTꢀ format.ꢀ Inꢀ responseꢀ toꢀ theꢀ OT_FAULT_
LIMITꢀbeingꢀexceeded,ꢀtheꢀdeviceꢀdoesꢀtheꢀfollowing:
Theꢀ POWER_GOOD_OFFꢀ commandꢀ setsꢀ theꢀ valueꢀ ofꢀ
the output voltage that causes the power-good state on
this channel to deassert after it has been asserted. The
POWER_GOOD_OFFꢀ levelꢀ shouldꢀ alwaysꢀ beꢀ setꢀ lowerꢀ
thanꢀtheꢀPOWER_GOOD_ONꢀlevel.ꢀTheꢀ2ꢀdataꢀbytesꢀareꢀ
inꢀDIRECTꢀformat.
WhenꢀtheꢀVOUTꢀlevelꢀofꢀaꢀpowerꢀsupplyꢀfallsꢀfromꢀgreaterꢀ
thanꢀPOWER_GOOD_ONꢀtoꢀlessꢀthanꢀPOWER_GOOD_
OFF,ꢀtheꢀdeviceꢀdoesꢀtheꢀfollowing:
1)ꢀ SetsꢀtheꢀTEMPERATUREꢀbitꢀinꢀSTATUS_WORD.
2)ꢀ SetsꢀtheꢀOT_FAULTꢀbitꢀinꢀSTATUS_TEMPERATUREꢀ
register.
1)ꢀ SetsꢀtheꢀPOWER_GOOD#ꢀbitꢀinꢀSTATUS_WORD.
3)ꢀ RespondsꢀasꢀspecifiedꢀinꢀtheꢀMFR_FAULT_RESPONSE.
2)ꢀ Setsꢀ theꢀ POWER_GOOD#ꢀ bitꢀ inꢀ STATUS_MFR_
SPECIFICꢀregisterꢀ(PAGESꢀ0–11).
4)ꢀ NotifiesꢀtheꢀhostꢀusingꢀALERTꢀassertionꢀ(ifꢀenabledꢀinꢀ
MFR_MODE).
Note:ꢀ Ifꢀ theꢀ POWER_GOOD_ONꢀ valueꢀ isꢀ configuredꢀ toꢀ
beꢀlowerꢀthanꢀtheꢀPOWER_GOOD_OFFꢀvalue,ꢀtheꢀdeviceꢀ
setsꢀtheꢀPOWER_GOOD_OFFꢀtoꢀbeꢀequalꢀtoꢀtheꢀPOWER_
GOOD_ONꢀvalue.ꢀConversely,ꢀifꢀtheꢀPOWER_GOOD_OFFꢀ
valueꢀisꢀconfiguredꢀtoꢀbeꢀhigherꢀthanꢀtheꢀPOWER_GOOD_
ONꢀvalue,ꢀtheꢀdeviceꢀsetsꢀtheꢀPOWER_GOOD_ONꢀtoꢀbeꢀ
equalꢀtoꢀtheꢀPOWER_GOOD_OFFꢀvalue.
OT_WARN_LIMIT (51h)
Theꢀ OT_WARN_LIMITꢀ commandꢀ setsꢀ theꢀ temperature,ꢀ
in degrees Celsius, of the selected temperature sensor
at which an overtemperature warning is detected. The
monitoredꢀtemperatureꢀmustꢀdropꢀbyꢀatꢀleastꢀ4°Cꢀbelowꢀ
the limit before the warning is allowed to clear. The 2
dataꢀ bytesꢀ areꢀ inꢀ DIRECTꢀ format.ꢀ Inꢀ responseꢀ toꢀ theꢀ
OT_WARN_LIMITꢀbeingꢀexceeded,ꢀtheꢀdeviceꢀdoesꢀtheꢀ
following:
TON_DELAY (60h)
Inꢀ theꢀ PMBusꢀ sequencingꢀ configuration,ꢀ TON_DELAYꢀ
setsꢀ theꢀ time,ꢀ inꢀ milliseconds,ꢀ fromꢀ whenꢀ aꢀ STARTꢀ
conditionꢀ isꢀ receivedꢀ untilꢀ theꢀ PSENnꢀ outputꢀ isꢀ asserted.ꢀ
Ifꢀ theꢀ PSENn/GPOnꢀ outputꢀ hasꢀ beenꢀ configuredꢀ (withꢀ
theꢀ MFR_PSEN_CONFIGꢀ command)ꢀ asꢀ aꢀ PG/GPIꢀ orꢀ
alarm, then this command can be used to delay the assertion
ofꢀtheꢀoutput.ꢀTheꢀ2ꢀdataꢀbytesꢀareꢀinꢀDIRECTꢀformat.
1)ꢀ SetsꢀtheꢀTEMPERATUREꢀbitꢀinꢀSTATUS_WORD.
2)ꢀ SetsꢀtheꢀOT_WARNꢀbitꢀinꢀSTATUS_TEMPERATUREꢀ
register.
3)ꢀ NotifiesꢀtheꢀhostꢀthroughꢀALERTꢀassertionꢀ(ifꢀenabledꢀ
inꢀMFR_MODE).
TOFF_DELAY (64h)
POWER_GOOD_ON (5Eh)
TOFF_DELAYꢀ setsꢀ theꢀ time,ꢀ inꢀ milliseconds,ꢀ fromꢀ whenꢀ
aꢀ STOPꢀ conditionꢀ isꢀ receivedꢀ (aꢀ soft-offꢀ OPERATIONꢀ
command,ꢀorꢀthroughꢀtheꢀCONTROLnꢀpinsꢀwhenꢀenabled)ꢀ
untilꢀtheꢀPSENnꢀoutputꢀisꢀdeasserted.ꢀWhenꢀcommandedꢀ
toꢀ turnꢀ offꢀ immediatelyꢀ (eitherꢀ throughꢀ theꢀ OPERATIONꢀ
commandꢀorꢀtheꢀCONTROLnꢀpins),ꢀtheꢀTOFF_DELAYꢀvalueꢀ
isꢀignored.ꢀIfꢀtheꢀPSENn/GPOnꢀoutputꢀhasꢀbeenꢀconfiguredꢀ
(withꢀtheꢀMFR_PSEN_CONFIGꢀcommand)ꢀasꢀaꢀPG/GPIꢀorꢀ
alarm, then this command can be used to delay the
deassertionꢀofꢀtheꢀoutput.ꢀTheꢀ2ꢀdataꢀbytesꢀareꢀinꢀDIRECTꢀ
format.
Theꢀ POWER_GOOD_ONꢀ commandꢀ setsꢀ theꢀ valueꢀ ofꢀ
the output voltage that the channel must exceed for a
power-good state to be declared on this channel. All
channels configured as voltage monitoring, with or without
sequencing,ꢀshouldꢀhaveꢀtheirꢀvoltagesꢀaboveꢀPOWER_
GOOD_ONꢀ forꢀ power-supplyꢀ marginingꢀ toꢀ begin.ꢀ Theꢀ
POWER_GOOD_ONꢀthresholdꢀisꢀalsoꢀusedꢀtoꢀdetermineꢀ
ifꢀTON_MAX_FAULT_LIMITꢀisꢀexceeded.ꢀTheꢀPOWER_
GOOD_ONꢀ levelꢀ shouldꢀ alwaysꢀ beꢀ setꢀ higherꢀ thanꢀ theꢀ
POWER_GOOD_OFFꢀ level.ꢀ Theꢀ 2ꢀ dataꢀ bytesꢀ areꢀ inꢀ
DIRECTꢀformat.
Note:ꢀ Forꢀ GPOsꢀ configuredꢀ toꢀ assert/deassertꢀ basedꢀ
onꢀ Powerꢀ Goodꢀ (PG)ꢀ conditionꢀ ofꢀ monitoredꢀ channels:
If the voltage of a monitored channel repeatedly crosses over
theꢀPGꢀthresholdꢀduringꢀtheꢀGPO'sꢀTON_DELAYꢀorꢀTOFF_
DELAYꢀ time,ꢀ rarelyꢀ theꢀ GPOꢀ mightꢀ getꢀ assertedꢀ orꢀ deas-
serted incorrectly at the end of the delay time. To avoid this
scenario,ꢀconfigureꢀbothꢀTON_DELAYꢀandꢀTOFF_DELAYꢀtoꢀ
0ms.ꢀAlternatively,ꢀsetꢀbothꢀTON_DELAYꢀandꢀTOFF_DELAYꢀ
toꢀnonzeroꢀvalues.
POWER_GOOD_ONꢀ shouldꢀ beꢀ setꢀ higherꢀ thanꢀ VOUT_
UV_FAULT_LIMITꢀandꢀVOUT_UV_WARN_LIMITꢀbecauseꢀtheirꢀ
functionality does not become active until the measured output
voltageꢀrisesꢀaboveꢀtheꢀPOWER_GOOD_ONꢀthreshold.
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
1)ꢀ SetsꢀtheꢀVOUTꢀbitꢀinꢀSTATUS_WORD.
TON_MAX_FAULT_LIMIT (62h)
TON_MAX_FAULT_LIMITꢀ setsꢀ anꢀ upperꢀ timeꢀ limit,ꢀ inꢀ
milliseconds,ꢀ fromꢀ whenꢀ theꢀ PSENnꢀ outputꢀ isꢀ assertedꢀ
untilꢀtheꢀoutputꢀvoltageꢀcrossesꢀtheꢀPOWER_GOOD_ONꢀ
threshold.ꢀTheꢀ2ꢀdataꢀbytesꢀareꢀinꢀDIRECTꢀformat.ꢀIfꢀtheꢀ
valueꢀisꢀzero,ꢀthenꢀtheꢀlimitꢀisꢀdisabled.ꢀInꢀresponseꢀtoꢀtheꢀ
TON_MAX_FAULT_LIMITꢀ beingꢀ exceeded,ꢀ theꢀ deviceꢀ
doesꢀtheꢀfollowing:
2)ꢀ SetsꢀtheꢀTON_MAX_FAULTꢀbitꢀinꢀSTATUS_VOUT.
3)ꢀ RespondsꢀasꢀspecifiedꢀinꢀtheꢀMFR_FAULT_
RESPONSE.
4)ꢀ NotifiesꢀtheꢀhostꢀusingꢀALERTꢀassertionꢀ(ifꢀenabledꢀinꢀ
MFR_MODE).
STATUS_VOUT
(PAGES 0–15)
EVENT
EVENT
EVENT
EVENT
EVENT
LATCH VOUT_OV_FAULT
LATCH VOUT_OV_WARN
LATCH VOUT_UV_FAULT
LATCH VOUT_UV_WARN
LATCH TON_MAX_FAULT
OR
STATUS_CML
(ALL PAGES)
EVENT
EVENT
EVENT
EVENT
EVENT
FAULT_LOG_FULL
LATCH
LATCH
LATCH
LATCH
DATA_FAULT
COMM_FAULT
MAIN_FAULT
OR
BACKUP_FAULT
STATUS_IOUT
(PAGES 0–15)
EVENT
EVENT
LATCH
LATCH
OC_FAULT
OC_WARN
OR
OR
STATUS_WORD
(ALL PAGES)
STATUS_TEMPERATURE
(PAGES 16–20)
VOUT_OV
VOUT
EVENT
EVENT
LATCH
LATCH
OT_WARN
OT_FAULT
CML
IOUT_OC
STATUS_MFR_SPECIFIC
(PAGE 0–15)
IOUT
OR
TEMPERATURE
EVENT
EVENT
EVENT
OFF
POWER_GOOD#
MARGIN_FAULT
SYS_OFF
POWER_GOOD#
MARGIN
LATCH
MFR
STATUS_MFR_SPECIFIC
(PAGES 255)
EVENT
EVENT
EVENT
EVENT
EVENT
LOCK
POR
LATCH
LATCH
LATCH
FAULT_INPUT
WATCHDOG
CONTROL#
OR
ALERT
OUTPUT
CLEAR
CLEAR_FAULTS COMMAND
LATCH
OR
ALERT RESPONSE ADDRESS (ARA)
RECEIVED AND ARBITRATION WON
AND
ALERT BIT IN MFR_MODE
NOTE 1: IF AN EVENT IS STILL PRESENT WHEN THE CLEAR_FAULTS COMMAND IS ISSUED, THE BIT IS IMMEDIATELY ASSERTED ONCE AGAIN.
NOTE 2: WHEN THE ALERT LATCH IS CLEARED, IF ANY EVENTS ARE STILL PRESENT, THEY DO NOT REASSERT THE ALERT OUTPUT.
Figure 7. Status Register Organization
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
STATUS_WORD (79h)
STATUS_VOUT (7Ah)
Theꢀ STATUS_WORDꢀ commandꢀ returnsꢀ 2ꢀ bytesꢀ ofꢀ
information with a summary of the reason for a fault. The
STATUS_WORDꢀmessageꢀcontentꢀisꢀdescribedꢀinꢀTable 19.
TheꢀSTATUS_VOUTꢀcommandꢀreturnsꢀ1ꢀbyteꢀofꢀinforma-
tion with contents, as described in Tableꢀ20. All the bits
inꢀ STATUS_VOUTꢀ areꢀ latched.ꢀ Whenꢀ cleared,ꢀ theꢀ bitsꢀ
are set again if the condition persists, or in the case of
TON_MAX_FAULT,ꢀwhenꢀtheꢀeventꢀoccursꢀagain.
Table 19. STATUS_WORD (79h)
BIT
NAME
MEANING
Anꢀoutputꢀvoltageꢀfaultꢀorꢀwarning,ꢀorꢀTON_MAX_FAULT_LIMITꢀorꢀMFR_TON_SEQ_MAX
has occurred.
15
VOUT
14
13
12
IOUT
0
An overcurrent fault or warning has occurred.
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
MFR
AꢀbitꢀinꢀSTATUS_MFR_SPECIFICꢀ(PAGEꢀ=ꢀ255)ꢀhasꢀbeenꢀset.
Anyꢀpower-supplyꢀvoltageꢀhasꢀfallenꢀfromꢀPOWER_GOOD_ONꢀtoꢀlessꢀthanꢀPOWER_GOOD_OFFꢀ
(logicalꢀORꢀofꢀallꢀtheꢀPOWER_GOOD#ꢀbitsꢀinꢀSTATUS_MFR_SPECIFIC).
11
POWER_GOOD#
10
9
0
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
A margining fault has occurred.
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
0
MARGIN
0
8
7
Setꢀwhenꢀanyꢀofꢀtheꢀpowerꢀsuppliesꢀareꢀsequencedꢀoffꢀ(logicalꢀORꢀofꢀallꢀtheꢀOFFꢀbitsꢀin
STATUS_MFR_SPECIFC).
6
SYS_OFF
5
4
3
2
1
0
VOUT_OV
An overvoltage fault has occurred.
An overcurrent fault has occurred.
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
IOUT_OC
0
TEMPERATURE
A temperature fault or warning has occurred.
A communication, memory, or logic fault has occurred.
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
CML
0
Note: The setting of the SYS_OFF and POWER_GOOD# bits do not assert the ALERT signal.
Table 20. STATUS_VOUT (7Ah)
BIT
7
NAME
MEANING
LATCHED
Yes
Yes
Yes
Yes
—
VOUT_OV_FAULT
VOUTꢀovervoltageꢀfault.
6
VOUT_OV_WARN
VOUTꢀovervoltageꢀwarning.
VOUTꢀundervoltageꢀwarning.
VOUTꢀundervoltageꢀfault.
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
5
VOUT_UV_WARN
4
VOUT_UV_FAULT
3
0
2
TON_MAX_FAULT
TON_MAX_FAULT_LIMITꢀorꢀMFR_TON_SEQ_MAXꢀfault.
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
Yes
—
1
0
0
0
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
—
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
theꢀbitsꢀinꢀSTATUS_VOUTꢀareꢀlatched.ꢀWhenꢀcleared,ꢀtheꢀ
bits are set again if the condition persists.
STATUS_IOUT (7Bh)
Theꢀ STATUS_IOUTꢀ commandꢀ returnsꢀ 1ꢀ byteꢀ ofꢀ
information with contents, as described in Table 21. All the
bitsꢀinꢀSTATUS_IOUTꢀareꢀlatched.ꢀWhenꢀcleared,ꢀtheꢀbitsꢀ
are set again if the condition persists.
STATUS_CML (7Eh)
TheꢀSTATUS_CMLꢀcommandꢀreturnsꢀ1ꢀbyteꢀofꢀinformationꢀ
withcontents, asdescribedinTable23.ꢀTheꢀCOMM_FAULT,ꢀ
DATA_FAULT,ꢀ MAIN_FAULT,ꢀ andꢀ BACKUP_FAULTꢀ bitsꢀ
areꢀlatched.ꢀWhenꢀcleared,ꢀtheꢀbitsꢀareꢀsetꢀagainꢀwhenꢀtheꢀ
eventꢀ occursꢀ again.ꢀ Theꢀ FAULT_LOG_FULLꢀ bitꢀ reflectsꢀ
the current real-time state of the fault log.
STATUS_TEMPERATURE (7Dh)
TheꢀSTATUS_TEMPERATUREꢀcommandꢀreturnsꢀ1ꢀbyteꢀ
of information with contents, as described in Table 22. All
Table 21. STATUS_IOUT (7Bh)
BIT
7
NAME
MEANING
LATCHED
IOUT_OC_FAULT
IOUTꢀovercurrentꢀfault.
Yes
—
6
0
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
IOUTꢀovercurrentꢀwarning.
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
5
IOUT_OC_WARN
Yes
—
4
0
0
0
0
0
3
—
2
—
1
—
0
—
Table 22. STATUS_TEMPERATURE (7Dh)
BIT
7
NAME
MEANING
LATCHED
OT_FAULT
Overtemperature fault.
Yes
Yes
—
6
OT_WARN
Overtemperature warning.
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
5
0
0
0
0
0
0
4
—
3
—
2
—
1
—
0
—
Table 23. STATUS_CML (7Eh)
BIT
7
NAME
COMM_FAULT
DATA_FAULT
0
MEANING
An invalid or unsupported command has been received.
An invalid or unsupported data has been received.
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
LATCHED
Yes
Yes
—
6
5
4
0
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
—
3
0
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
—
2
BACKUP_FAULT
MAIN_FAULT
FAULT_LOG_FULL
FlashꢀBACKUPꢀmemoryꢀarrayꢀisꢀcorrupt.
FlashꢀMAINꢀmemoryꢀarrayꢀisꢀcorrupt.
MFR_NV_FAULT_LOGꢀisꢀfullꢀandꢀneedsꢀtoꢀbeꢀcleared.
Yes
Yes
No
1
0
Notes: When the NV fault log overwrite is enabled (NV_LOG_OVERWRITE = 1 in MFR_MODE), FAULT_LOG_FULL is set when the
fault log is full, but clears when the fault log is overwritten since two fault logs are cleared before each overwrite; the setting of the
BACKUP_FAULT and MAIN_FAULT bits do not assert the ALERT signal.
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
STATUS_MFR_SPECIFIC (80h)
TheꢀSTATUS_MFR_SPECIFICꢀmessageꢀcontentꢀvariesꢀbasedꢀonꢀtheꢀselectedꢀPAGE,ꢀandꢀisꢀdescribedꢀinꢀTable 24 and
Table 25.
Table 24. STATUS_MFR_SPECIFIC (80h) (for PAGES 0–11)
BIT
NAME
MEANING
LATCHED
Forꢀenabledꢀchannels,ꢀthisꢀbitꢀreflectsꢀtheꢀoutputꢀstateꢀofꢀtheꢀsequencerꢀandꢀisꢀsetꢀ
whenꢀPSENnꢀisꢀnotꢀassertedꢀdueꢀtoꢀeitherꢀaꢀsequencingꢀdelayꢀorꢀaꢀfault,ꢀorꢀtheꢀpowerꢀ
supplyꢀbeingꢀturnedꢀoff.ꢀThisꢀbitꢀisꢀalwaysꢀclearedꢀwhenꢀtheꢀchannelꢀisꢀdisabled.ꢀIfꢀ
PSENnꢀisꢀreconfiguredꢀasꢀaꢀGPO,ꢀthisꢀbitꢀdoesꢀnotꢀreflectꢀtheꢀstateꢀofꢀtheꢀpin.
7
OFF
No
6
5
4
3
0
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
—
—
0
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
0
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
—
MARGIN_FAULT
This bit is set if the device cannot properly close-loop margin the power supply.
Yes
Thisꢀbitꢀisꢀsetꢀwhenꢀtheꢀpower-supplyꢀvoltageꢀhasꢀfallenꢀfromꢀPOWER_GOOD_ONꢀtoꢀ
lessꢀthanꢀPOWER_GOOD_OFF.ꢀOnꢀdeviceꢀreset,ꢀthisꢀbitꢀisꢀsetꢀuntilꢀtheꢀpowerꢀsupplyꢀ
isꢀgreaterꢀthanꢀPOWER_GOOD_ON.
2
POWER_GOOD#
No
1
0
0
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
—
—
0
Note: The setting of the OFF and POWER_GOOD# bits do not assert the ALERT signal.
Table 25. STATUS_MFR_SPECIFIC (for PAGE 255)
BIT
7
NAME
LOCK
MEANING
LATCHED
No
Setꢀwhenꢀtheꢀdeviceꢀisꢀpasswordꢀprotectedꢀ(Noteꢀ1).
SetꢀeachꢀtimeꢀanyꢀofꢀtheꢀFAULTnꢀinputsꢀareꢀpulledꢀlowꢀ(Noteꢀ2).
SetꢀeachꢀtimeꢀaꢀdeviceꢀPowerꢀOnꢀResetꢀ(POR)ꢀoccursꢀ(Noteꢀ4).
6
FAULT_INPUT
POR
Yes
5
Yes
Setꢀuponꢀdeviceꢀresetꢀwhenꢀtheꢀinternalꢀwatchdogꢀhasꢀcausedꢀtheꢀdeviceꢀresetꢀ
(Note4).
4
WATCHDOG_INT
Yes
3
2
1
0
CONTROL#
SetꢀeachꢀtimeꢀtheꢀCONTROLnꢀinputsꢀareꢀdeassertedꢀ(Noteꢀ3).
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
Yes
—
0
0
0
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
—
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
—
Note 1: Setting the LOCK bit or the POR bit does not assert the ALERT signal.
Note 2: Applies to all FAULTn inputs. The fault status bit is set even if the FAULTn pin is configured in MFR_NV_LOG_CONFIG to
ignore FAULTn pins. If FAULT1 and FAULT2 are disabled, they do not affect this bit.
Note 3: Either the CONTROL0 or CONTROL1 pin can set this bit. ON_OFF_CONFIG must be configured to use the CONTROLn
pins for this status bit to function.
Note 4: This bit is latched when set and can be cleared by either issuing the CLEAR_FAULTS command or by reading the
STATUS_MFR_SPECIFIC register.
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measured
(not
commanded)
output
voltage.
READ_VOUTisꢀ
compliant.Theꢀcommandꢀhasꢀ1ꢀdataꢀbyte.ꢀBitsꢀ7:4ꢀindicateꢀtheꢀ
MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
READ_VOUT (8Bh)
MFR_REVISION (9Bh)
Theꢀ READ_VOUTꢀ commandꢀ returnsꢀ theꢀ actualꢀ
Theꢀ MFR_REVISIONꢀ commandꢀ returnsꢀ twoꢀ textꢀ (ISO/
IECꢀ8859-1)ꢀ charactersꢀthatꢀcontainꢀtheꢀdeviceꢀrevisionꢀ
numbersꢀforꢀhardwareꢀ(upperꢀbyte)ꢀandꢀfirmwareꢀ(lowerꢀ
byte).ꢀThisꢀcommandꢀisꢀread-only.
measuredꢀ andꢀ updatedꢀ everyꢀ 5ms.ꢀ Ifꢀ theꢀ RSn/GPInꢀ
isꢀ configuredꢀ toꢀ beꢀ aꢀ general-purposeꢀ inputꢀ (GPI),ꢀ byꢀ
configuringꢀtheꢀSELECTꢀbitsꢀinꢀMFR_CHANNEL_CONFIGꢀ
toꢀ eitherꢀ 30hꢀ orꢀ 34h,ꢀ thenꢀ READ_VOUTꢀ reportsꢀ 0000hꢀ
whenꢀtheꢀGPInꢀinputꢀisꢀinactiveꢀandꢀ0001hꢀwhenꢀtheꢀGPInꢀ
inputꢀisꢀactive.ꢀTheꢀ2ꢀdataꢀbytesꢀareꢀinꢀDIRECTꢀformat.
MFR_LOCATION (9Ch)
Theꢀ MFR_LOCATIONꢀ commandꢀ loadsꢀ theꢀ deviceꢀ
withꢀ textꢀ (ISO/IECꢀ 8859-1)ꢀ charactersꢀ thatꢀ identifyꢀ theꢀ
facility that manufactures the power supply. The maximum
numberꢀofꢀcharactersꢀisꢀ8.ꢀThisꢀdataꢀisꢀwrittenꢀtoꢀinternalꢀ
flashꢀ usingꢀ theꢀ STORE_DEFAULT_ALLꢀ command.ꢀ Theꢀ
factory-defaultꢀtextꢀstringꢀvalueꢀisꢀ10101010.
READ_IOUT (8Ch)
TheꢀREAD_IOUTꢀcommandꢀreturnsꢀtheꢀlatestꢀmeasuredꢀ
currentꢀ value.ꢀ READ_IOUTꢀ isꢀ measuredꢀ andꢀ updatedꢀ
everyꢀ5ms.ꢀTheꢀ2ꢀdataꢀbytesꢀareꢀinꢀDIRECTꢀformat.
MFR_DATE (9Dh)
READ_TEMPERATURE_1 (8Dh)
Theꢀ MFR_DATEꢀ commandꢀ loadsꢀ theꢀ deviceꢀ withꢀ textꢀ
(ISO/IECꢀ 8859-1)ꢀ charactersꢀ thatꢀ identifyꢀ theꢀ dateꢀ ofꢀ
manufacture of the power supply. The maximum number
ofꢀ charactersꢀ isꢀ 8.ꢀ Thisꢀ dataꢀ isꢀ writtenꢀ toꢀ internalꢀ flashꢀ
usingꢀtheꢀSTORE_DEFAULT_ALLꢀcommand.ꢀTheꢀfactory-
defaultꢀtextꢀstringꢀvalueꢀisꢀ10101010.
Theꢀ READ_TEMPERATURE_1ꢀ commandꢀ returnsꢀ theꢀ
temperature returned from the temperature sensor.
READ_TEMPERATURE_1ꢀ returnsꢀ 7FFFhꢀ ifꢀ theꢀ sensorꢀ
isꢀ faultyꢀ andꢀ 0000hꢀ ifꢀ theꢀ sensorꢀ isꢀ disabled.ꢀ READ_
TEMPERATURE_1ꢀ isꢀ measuredꢀ andꢀ updatedꢀ onceꢀ perꢀ
second.ꢀTheꢀ2ꢀdataꢀbytesꢀareꢀinꢀDIRECTꢀformat.
MFR_SERIAL (9Eh)
PMBUS_REVISION (98h)
Theꢀ PMBUS_REVISIONꢀ commandꢀ returnsꢀ theꢀ
revisionꢀofꢀtheꢀPMBusꢀspecificationꢀtoꢀwhichꢀtheꢀdeviceꢀisꢀ
Theꢀ MFR_SERIALꢀ commandꢀ loadsꢀ theꢀ deviceꢀ withꢀ textꢀ
(ISO/IECꢀ 8859-1)ꢀ charactersꢀ thatꢀ uniquelyꢀ identifyꢀ theꢀ
device.ꢀTheꢀmaximumꢀnumberꢀofꢀcharactersꢀisꢀ8.ꢀThisꢀdataꢀ
isꢀ writtenꢀ toꢀ internalꢀ flashꢀ usingꢀ theꢀ STORE_DEFAULT_
ALLꢀ command.ꢀ Theꢀ factoryꢀ defaultꢀ textꢀ stringꢀ valueꢀ isꢀ
10101010.ꢀTheꢀupperꢀ4ꢀbytesꢀofꢀMFR_SERIALꢀareꢀusedꢀ
to unlock a device that has been password protected. The
lowerꢀ4ꢀbytesꢀofꢀMFR_SERIALꢀareꢀnotꢀusedꢀtoꢀunlockꢀaꢀ
device and they can be set to any value.
revisionꢀ ofꢀ theꢀ PMBusꢀ specificationꢀ Partꢀ Iꢀ toꢀ whichꢀ theꢀ
deviceꢀ isꢀ compliant.ꢀ Bitsꢀ 3:0ꢀ indicateꢀ theꢀ revisionꢀ ofꢀ
theꢀ PMBusꢀ specificationꢀ Partꢀ IIꢀ toꢀ whichꢀ theꢀ deviceꢀ isꢀ
compliant.ꢀ Thisꢀ commandꢀ isꢀ read-only.ꢀ Theꢀ PMBUS_
REVISIONꢀvalueꢀreturnedꢀisꢀalwaysꢀ11h,ꢀwhichꢀindicatesꢀ
thatꢀ theꢀ deviceꢀ isꢀ compliantꢀ withꢀ Partꢀ I,ꢀ Revꢀ 1.1ꢀ andꢀ
PartꢀII,ꢀRevꢀ1.1.
MFR_MODE (D1h)
Theꢀ MFR_MODEꢀ commandꢀ isꢀ usedꢀ toꢀ configureꢀ theꢀ
device to support manufacturer-specific commands.
Theꢀ MFR_MODEꢀ commandꢀ shouldꢀ notꢀ beꢀ changedꢀ
whileꢀ powerꢀ suppliesꢀ areꢀ operating.ꢀ Theꢀ MFR_MODEꢀ
command is described in Table 26.
MFR_ID (99h)
TheꢀMFR_IDꢀcommandꢀreturnsꢀtheꢀtextꢀ(ISO/IECꢀ8859-1)ꢀ
characterꢀ ofꢀ theꢀ manufacturer’sꢀ (Maxim)ꢀ identification.ꢀ
TheꢀdefaultꢀMFR_IDꢀvalueꢀisꢀ4Dhꢀ(M).ꢀThisꢀcommandꢀisꢀ
read-only.
MFR_MODEL (9Ah)
Theꢀ MFR_MODELꢀ commandꢀ returnsꢀ theꢀ textꢀ (ISO/IECꢀ
8859-1)ꢀ characterꢀ ofꢀ theꢀ deviceꢀ modelꢀ number.ꢀ Theꢀ
defaultꢀMFR_MODELꢀvalueꢀisꢀ59hꢀ(Y).ꢀThisꢀcommandꢀisꢀ
read-only.
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Table 26. MFR_MODE (D1h)
BIT
NAME
MEANING
15:14
0
Theseꢀbitsꢀalwaysꢀreturnꢀaꢀ0.
0ꢀ=ꢀALERTꢀdisabledꢀ(deviceꢀdoesꢀnotꢀrespondꢀtoꢀARA).
1ꢀ=ꢀALERTꢀenabledꢀ(deviceꢀdoesꢀrespondꢀtoꢀARA).
13
ALERT
12
11
0
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
SOFT_RESET
Thisꢀbitꢀmustꢀbeꢀset,ꢀthenꢀclearedꢀandꢀsetꢀagainꢀwithinꢀ8msꢀforꢀaꢀsoftꢀresetꢀtoꢀoccur.
Thisꢀbitꢀmustꢀbeꢀset,ꢀthenꢀclearedꢀandꢀsetꢀagainꢀwithinꢀ8msꢀforꢀtheꢀdeviceꢀtoꢀbecomeꢀ
password protected. This bit is cleared when the password is unlocked. The device should
only be locked and then unlocked a maximum of 256 times before either a device reset is
issued or a device power cycle occurs.
10
LOCK
0
9:8
Theseꢀbitsꢀalwaysꢀreturnꢀaꢀ0.
TheseꢀbitsꢀselectꢀtheꢀADCꢀconversionꢀtime:
ADC_TIME[1:0]
ADCꢀCONVERSIONꢀTIME
00
01
10
11
1µs
2µs
4µs
8µs
7:6
5:4
ADC_TIME[1:0]
TheseꢀbitsꢀselectꢀtheꢀpostꢀADCꢀconversionꢀaveraging:
ADC_AVERAGE[1:0]
ADCꢀAVERAGING
NoꢀAveraging
Averageꢀ2ꢀSamples
Averageꢀ4ꢀSamples
Averageꢀ8ꢀSamples
00
01
10
11
ADC_AVERAGE[1:0]
These bits determine the number of samples to average before reporting the value in
MFR_IOUT_AVG:
IOUT_AVG[3:0]
0000
AVERAGING
1ꢀSample
IOUT_AVG[3:0]
1000
AVERAGING
256ꢀSamples
0001
0010
0011
0100
0101
0110
0111
2ꢀSamples
4ꢀSamples
8ꢀSamples
16ꢀSamples
32ꢀSamples
64ꢀSamples
128ꢀSamples
1001
1010
1011
1100
1101
1110
1111
512ꢀSamples
3:0
IOUT_AVG[3:0]
1024ꢀSamples
2048ꢀSamples
4096ꢀSamples
8192ꢀSamples
16,384ꢀSamples
32,768ꢀSamples
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PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Also,ꢀ eachꢀ PSENn/GPOnꢀ pinꢀ canꢀ beꢀ independentlyꢀ
configured to be active high or active low and either
push-pullꢀorꢀopenꢀdrainꢀusingꢀtheꢀHI_LOꢀandꢀPP_ODꢀbits,ꢀ
respectively.
MFR_PSEN_CONFIG (D2h)
Theꢀ MFR_PSEN_CONFIGꢀ commandꢀ isꢀ usedꢀ toꢀ con-
figureꢀ theꢀ individualꢀ PSENn/GPOnꢀ (whereꢀ nꢀ =ꢀ 0–11)ꢀ
outputs. This command should not be changed while the
powerꢀsuppliesꢀareꢀoperating.ꢀTheꢀMFR_PSEN_CONFIGꢀ
command is described in Table 27 and shown in Figureꢀ8.
Ifꢀ SELECT[2:0]ꢀ =ꢀ 011,ꢀ theꢀ PSENn/GPOnꢀ outputꢀ isꢀ
configured to assert when some combination of power
goodsꢀ (PGs)ꢀ andꢀ general-purposeꢀ inputsꢀ (GPIs)ꢀ fromꢀ
each channel are asserted. The channels that should
be used in this combination are selected using the
PG_GPI_SELECTꢀ bitsꢀ 31:16.ꢀ Ifꢀ theꢀ PG_GPI_SELECTꢀ
bit is cleared, then the associated channel is not used
inꢀtheꢀlogicalꢀcombinationꢀtoꢀassertꢀtheꢀGPOnꢀoutput.ꢀIfꢀ
theꢀPG_GPI_SELECTꢀbitꢀisꢀset,ꢀthenꢀtheꢀPGꢀorꢀGPIꢀfromꢀ
this channel is used in the logical combination to assert
orꢀ deassertꢀ theꢀ GPOnꢀ output.ꢀThisꢀ functionꢀ isꢀ usefulꢀ inꢀ
creating system power-good signals.
EachꢀPSENn/GPOnꢀpinꢀcanꢀbeꢀindependentlyꢀconfiguredꢀ
usingꢀtheꢀSELECT[2:0]ꢀbitsꢀtoꢀoneꢀofꢀtheꢀfollowing:
●ꢀ Enableꢀandꢀdisabledꢀpowerꢀsuppliesꢀ(SELECT[2:0]ꢀ=ꢀ
000)
●ꢀ Forceꢀpinꢀassertionꢀ(SELECT[2:0]ꢀ=ꢀ001)
●ꢀ Forceꢀpinꢀdeassertionꢀ(SELECT[2:0]ꢀ=ꢀ010)
●ꢀ Assertꢀwhenꢀallꢀenabledꢀchannelꢀpower-goodꢀ(PG)ꢀorꢀ
GPIꢀareꢀassertedꢀ(SELECT[2:0]ꢀ=ꢀ011)
●ꢀ Assertꢀ whenꢀ anyꢀ enabledꢀ alarmꢀ goesꢀ activeꢀ
(SELECT[2:0]ꢀ=ꢀ100)
Ifꢀ SELECT[2:0]ꢀ =ꢀ 100,ꢀ theꢀ PSENn/GPOnꢀ outputꢀ isꢀ
configured to assert when any of the enabled channel
alarms goes active. The channel alarms are enabled with
theꢀALARM_SELECTꢀbitsꢀ31:16.ꢀIfꢀtheꢀALARM_SELECTꢀ
bit is cleared, then the alarm from this channel is blocked.
Ifꢀ theꢀ ALARM_SELECTꢀ bitꢀ isꢀ set,ꢀ theꢀ alarmꢀ fromꢀ thisꢀ
channelꢀisꢀroutedꢀtoꢀanꢀORꢀfunctionꢀsuchꢀthatꢀanyꢀenabledꢀ
alarmꢀ assertsꢀ theꢀ GPOnꢀ output.ꢀ Theꢀ alarmꢀ functionꢀ isꢀ
chosenꢀ withꢀ theꢀ ALARM_CONFIGꢀ bitsꢀ inꢀ theꢀ MFR_
FAULT_RESPONSEꢀcommand.ꢀThisꢀfunctionꢀisꢀusefulꢀisꢀ
inꢀsystemꢀdebugꢀorꢀforꢀenablingꢀsystemꢀstatusꢀLEDs.
Ifꢀ theꢀ PSENn/GPOnꢀ outputꢀ isꢀ configuredꢀ toꢀ enableꢀ andꢀ
disableꢀ powerꢀ suppliesꢀ (SELECT[2:0]ꢀ =ꢀ 000),ꢀ thenꢀ theꢀ
associated input channel must also be configured to
monitorꢀvoltageꢀandꢀtoꢀsequenceꢀbyꢀsettingꢀtheꢀSELECTꢀ
bitsꢀ inꢀ MFR_CHANNEL_CONFIGꢀ toꢀ 10h.ꢀ Seeꢀ theꢀ
MFR_CHANNEL_CONFIG (E4h) for more details.
Table 27. MFR_PSEN_CONFIG (D2h)
BIT
NAME
MEANING
TheseꢀbitsꢀareꢀonlyꢀusedꢀifꢀSELECT[2:0]ꢀ=ꢀ011ꢀorꢀ100.ꢀEachꢀbitꢀcorrespondsꢀtoꢀoneꢀ
channelꢀ(deviceꢀchannelꢀNꢀ+ꢀ16ꢀ=ꢀbitꢀnumber):
SELECT[2:0]
BITꢀFUNCTION
Whenꢀthisꢀbitꢀisꢀcleared,ꢀtheꢀpowerꢀgoodꢀ(PG)ꢀorꢀGPIꢀfromꢀ
channelꢀNꢀisꢀnotꢀusedꢀinꢀtheꢀlogicalꢀANDꢀtoꢀassertꢀtheꢀGPOnꢀ
output.ꢀWhenꢀthisꢀbitꢀisꢀset,ꢀtheꢀPGꢀorꢀGPIꢀisꢀused.
PG_GPI_SELECT
ALARM_SELECT
31:16
011
Whenꢀthisꢀbitꢀisꢀcleared,ꢀtheꢀalarmꢀfromꢀchannelꢀNꢀisꢀblockedꢀ
fromꢀtheꢀlogicalꢀORꢀtoꢀassertꢀtheꢀGPOnꢀoutput.ꢀWhenꢀthisꢀbitꢀ
isꢀset,ꢀtheꢀalarmꢀsignalꢀisꢀroutedꢀtoꢀtheꢀlogicalꢀOR.
100
15:8
0
Theseꢀbitsꢀalwaysꢀreturnꢀaꢀ0.
0ꢀ=ꢀPSEN/GPOꢀpush-pullꢀoutput
1ꢀ=ꢀPSEN/GPOꢀopen-drainꢀoutput
7
PP_OD
0ꢀ=ꢀPSEN/GPOꢀactiveꢀlow
1ꢀ=ꢀPSEN/GPOꢀactiveꢀhigh
6
HI_LO
0
5:3
Theseꢀbitsꢀalwaysꢀreturnꢀaꢀ0.
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PMBus 16-Channel V/I Monitor and
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Table 27. MFR_PSEN_CONFIG (D2h) (continued)
BIT
NAME
MEANING
Theseꢀbitsꢀdetermineꢀtheꢀfunctionꢀselectedꢀonꢀtheꢀpin:
SELECT[2:0]
000
PSENn/GPOnꢀPINꢀFUNCTIONꢀSELECTED
ꢀPSENꢀoperation.*
001
ForceꢀGPOꢀassertion.
010
011
100
101
ForceꢀGPOꢀdeassertion.
2:0
SELECT[2:0]
PG/GPIꢀoperationꢀ(useꢀbitsꢀ31:16).
Alarmꢀoperationꢀ(useꢀbitsꢀ31:16).
FAULT2ꢀspecialꢀfunctionꢀ(onlyꢀPAGEꢀ10);
SEQꢀspecialꢀfunctionꢀ(onlyꢀPAGEꢀ11).
Reserved.
11x
*For proper sequencing, the SELECT bits in MFR_CHANNEL_CONFIG must set to 10h.
NOT AVAILABLE FOR
SEQ OR FAULT2
OR FORCE GPO ASSERTION
OR DEASSERTION
000
001
010
NOT AVAILABLE FOR
SEQ OR FAULT2
PSENx
(x = 0–11)
FORCE GPO ASSERTION
TON_DELAY
TOFF_DELAY
ACTIVE HIGH/LOW
10
PSENx/GPOx
(x = 0–9)
OPEN DRAIN/PUSH-PULL
FORCE GPO DEASSERTION
SELECT
16
16
ALARM0–
ALARM15
PSEN10
GPO10
FAULT2
16
100
011
AND
OR
SELECT
SELECT
16
FAULT2
SEQ
PG0/GPI0–
PG15/GPI15
PSEN11
GPO11
SEQ
16
AND
AND
OR
MFR_PSEN_CONFIG
BITS 31:16
BITS 2:0
BIT 6
BIT 7
NOTE: SIGNALS LISTED IN ITALICS ARE INTERNAL SIGNALS THAT CONNECT TO OTHER DEVICE FUNCTIONS.
SHADED BLOCKS ARE PMBus COMMANDS.
Figure 8. MFR_PSEN_CONFIG Functional Logic
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Delay Function
MFR_VOUT_MIN (D7h)
If a delay is configured either on or off, the input must
be continuously static through the delay time before the
outputꢀchangesꢀstate.ꢀSeeꢀtheꢀFigureꢀ9.
Theꢀ MFR_VOUT_MINꢀ commandꢀ returnsꢀ theꢀ minimumꢀ
actual measured output voltage. To reset this value, write
toꢀthisꢀcommandꢀwithꢀaꢀdataꢀvalueꢀofꢀ7FFFh.ꢀAnyꢀvaluesꢀ
written to this command are used as a comparison for
futureꢀminimumꢀupdates.ꢀTheꢀ2ꢀdataꢀbytesꢀareꢀinꢀDIRECTꢀ
format.
MFR_VOUT_PEAK (D4h)
TheꢀMFR_VOUT_PEAKꢀcommandꢀreturnsꢀtheꢀmaximumꢀ
actualꢀmeasuredꢀoutputꢀvoltage.ꢀToꢀresetꢀthisꢀvalueꢀtoꢀ0,ꢀ
writeꢀtoꢀthisꢀcommandꢀwithꢀaꢀdataꢀvalueꢀofꢀ0.ꢀAnyꢀvaluesꢀ
written to this command are used as a comparison for
futureꢀ peakꢀ updates.ꢀ Theꢀ 2ꢀ dataꢀ bytesꢀ areꢀ inꢀ DIRECTꢀ
format.
MFR_FW_SERIAL (E0h)
Theꢀ MFR_FW_SERIALꢀ commandꢀ storesꢀ theꢀ internalꢀ
firmware version loaded onto the device. This is a 16-bit
unsigned integer. The command is read-only.
MFR_IOUT_PEAK (D5h)
MFR_IOUT_AVG (E2h)
TheꢀMFR_IOUT_PEAKꢀcommandꢀreturnsꢀtheꢀmaximumꢀ
actualꢀmeasuredꢀcurrent.ꢀToꢀresetꢀthisꢀvalueꢀtoꢀ0,ꢀwriteꢀtoꢀ
thisꢀcommandꢀwithꢀaꢀdataꢀvalueꢀofꢀ0.ꢀAnyꢀvaluesꢀwrittenꢀtoꢀ
this command are used as a comparison for future peak
updates.ꢀTheꢀ2ꢀdataꢀbytesꢀareꢀinꢀDIRECTꢀformat.
Theꢀ MFR_IOUT_AVGꢀ commandꢀ returnsꢀ theꢀ calculatedꢀ
average current. The number of samples collected in the
averageꢀ beforeꢀ reportingꢀ theꢀ valueꢀ inꢀ MFR_IOUT_AVGꢀ
isꢀconfiguredꢀusingꢀtheꢀIOUT_AVGꢀbitsꢀinꢀMFR_MODE.ꢀ
Writesꢀtoꢀthisꢀcommandꢀareꢀignored.ꢀTheꢀ2ꢀdataꢀbytesꢀareꢀ
inꢀDIRECTꢀformat.
MFR_TEMPERATURE_PEAK (D6h)
MFR_NV_LOG_CONFIG (D8h)
TheꢀMFR_TEMPERATURE_PEAKꢀcommandꢀreturnsꢀtheꢀ
maximum measured temperature. To reset this value to
its lowest value, write to this command with a data value
ofꢀ8000h.ꢀAnyꢀotherꢀvaluesꢀwrittenꢀbyꢀthisꢀcommandꢀareꢀ
used as a comparison for future peak updates. The 2 data
bytesꢀareꢀinꢀDIRECTꢀformat.
Theꢀ MFR_NV_LOG_CONFIGꢀ commandꢀ isꢀ usedꢀ toꢀ
configure the operation of the nonvolatile fault logging in
theꢀ device.ꢀ Theꢀ MFR_NV_LOG_CONFIGꢀ commandꢀ isꢀ
described in Tableꢀ28.
INPUT
OFF DELAY
OFF DELAY
ON DELAY
ON DELAY
OUTPUT
Figure 9. Input-to-Output Delay Action
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Table 28. MFR_NV_LOG_CONFIG (D8h)
BIT
NAME
MEANING
Settingꢀthisꢀbitꢀtoꢀaꢀ1,ꢀforcesꢀtheꢀdeviceꢀtoꢀlogꢀdataꢀintoꢀtheꢀnonvolatileꢀfaultꢀlog.ꢀOnceꢀ
set, the device clears this bit when the action is completed. Host must set again for
subsequentꢀaction.ꢀIfꢀanꢀerrorꢀoccursꢀduringꢀthisꢀaction,ꢀtheꢀdeviceꢀsetsꢀtheꢀCMLꢀbitꢀinꢀ
STATUS_WORD;ꢀnoꢀbitsꢀareꢀsetꢀinꢀSTATUS_CML.
15
FORCE_NV_FAULT_LOG
Settingꢀthisꢀbitꢀtoꢀaꢀ1,ꢀforcesꢀtheꢀdeviceꢀtoꢀclearꢀtheꢀnonvolatileꢀfaultꢀlogꢀbyꢀwritingꢀFFhꢀtoꢀ
all byte locations. Once set, the device clears this bit when the action is completed. Host
must set again for subsequent action. If an error occurs during this action, the device
setsꢀtheꢀCMLꢀbitꢀinꢀSTATUS_WORD;ꢀnoꢀbitsꢀareꢀsetꢀinꢀSTATUS_CML.ꢀWhileꢀclearingꢀtheꢀ
faultꢀlog,ꢀmonitoringꢀisꢀstoppedꢀandꢀcommandsꢀshouldꢀnotꢀbeꢀsentꢀtoꢀtheꢀPMBusꢀport.
14
CLEAR_NV_FAULT_LOG
13:11
10
0
Theseꢀbitsꢀalwaysꢀreturnꢀaꢀ0.
ThisꢀbitꢀdeterminesꢀtheꢀsourceꢀofꢀtheꢀdataꢀwrittenꢀintoꢀtheꢀT0ꢀlocationꢀofꢀeachꢀpageꢀwhenꢀ
a nonvolatile fault log is written.
0ꢀ=ꢀLogꢀtheꢀlastꢀregularꢀcollectionꢀintervalꢀADCꢀreading
1ꢀ=ꢀReadꢀtheꢀlatestꢀADCꢀvalueꢀbeforeꢀlogging
NV_LOG_T0_CONFIG
0ꢀ=ꢀDoꢀnotꢀoverwriteꢀtheꢀNVꢀfaultꢀlog
1ꢀ=ꢀOverwriteꢀtheꢀNVꢀfaultꢀlogꢀonceꢀitꢀisꢀfull*
9
NV_LOG_OVERWRITE
NV_LOG_DEPTH[1:0]
TheseꢀbitsꢀdetermineꢀtheꢀdepthꢀofꢀtheꢀNVꢀfaultꢀlog:
ADCꢀRESULTꢀCOLLECTIONꢀ
NV_LOG_DEPTH[1:0]
INTERVAL
5ms
20ms
80ms
160ms
NVꢀFAULTꢀLOGꢀDEPTH
00
01
10
11
15ms
60ms
240ms
480ms
8:7
0ꢀ=ꢀDoꢀnotꢀwriteꢀNVꢀfaultꢀlogꢀwhenꢀFAULT0 pin is externally pulled low.
1ꢀ=ꢀWriteꢀNVꢀfaultꢀlogꢀwhenꢀFAULT0 pin is externally pulled low.
N
NV_LOG_FAULT0
NV_LOG_FAULT1
0ꢀ=ꢀDoꢀnotꢀwriteꢀNVꢀfaultꢀlogꢀwhenꢀFAULT1 pin is externally pulled low.
1ꢀ=ꢀWriteꢀNVꢀfaultꢀlogꢀwhenꢀFAULT1 pin is externally pulled low and the FAULT1 pin is
enabled.
5
0ꢀ=ꢀDoꢀnotꢀwriteꢀNVꢀfaultꢀlogꢀwhenꢀFAULT2 pin is externally pulled low.
1ꢀ=ꢀWriteꢀNVꢀfaultꢀlogꢀwhenꢀFAULT2 pin is externally pulled low and the FAULT2 pin is
enabled.
4
NV_LOG_FAULT2
0
3:0
Theseꢀbitsꢀalwaysꢀreturnꢀaꢀ0.
*The device clears two fault logs at a time when overwrite is enabled.
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
configuredꢀ toꢀ monitorꢀ withꢀ bitsꢀ 26:24ꢀ inꢀ MFR_FAULT_
RESPONSE,ꢀtheꢀpower-upꢀsequencingꢀbegins.
MFR_FAULT_RESPONSE (D9h)
Theꢀ MFR_FAULT_RESPONSEꢀ commandꢀ speci-
fies the response to each fault or warning condition
supportedꢀbyꢀtheꢀdevice.ꢀInꢀresponseꢀtoꢀaꢀfault/warning,ꢀtheꢀ
deviceꢀalwaysꢀreportsꢀtheꢀfault/warningꢀinꢀtheꢀappropriateꢀ
status register and asserts the ALERTꢀoutputꢀ(ifꢀenabledꢀ
inꢀ MFR_MODE).ꢀAꢀ CMLꢀ faultꢀ cannotꢀ causeꢀ anyꢀ deviceꢀ
action other than setting the status bit and asserting the
ALERTꢀoutput.ꢀTheꢀMFR_FAULT_RESPONSEꢀcommandꢀ
is described in Tableꢀ30 and shown in Figureꢀ10.
GlobalꢀchannelsꢀmustꢀassertꢀaꢀFAULTn pin and respond
to that FAULTn pin for the channel to shut down.
LOCAL vs. GLOBAL Channels
Withꢀ theꢀ MFR_FAULT_RESPONSEꢀ commandꢀ (bitꢀ 14),ꢀ
each power-supply channel can be tagged as either being
LOCALꢀorꢀGLOBAL.ꢀWhenꢀbitꢀ14ꢀisꢀcleared,ꢀtheꢀchannelꢀ
isꢀ configuredꢀ asꢀ aꢀ LOCALꢀ channel,ꢀ whichꢀ meansꢀ thatꢀ aꢀ
detectedꢀ faultꢀ onlyꢀ affectsꢀ thisꢀ channelꢀ (orꢀ page).ꢀ Withꢀ
theꢀ RESPONSEꢀ bitsꢀ inꢀ theꢀ MFR_FAULT_RESPONSEꢀ
command, the device can be configured to respond differ-
entlyꢀtoꢀeachꢀpossibleꢀfault.ꢀWhenꢀbitꢀ14ꢀisꢀset,ꢀtheꢀchannelꢀ
isꢀ configuredꢀ asꢀ aꢀ GLOBALꢀ channelꢀ whichꢀ meansꢀ thatꢀ
a detected fault on this channel can assert all enabled
FAULTn outputs. The FAULTn outputs that are enabled are
selectedꢀwithꢀbitsꢀ18:16.ꢀOnlyꢀGLOBALꢀchannelsꢀrespondꢀ
to FAULTn pins that are asserted. The FAULTn pins that
the channel should respond to are assigned with bits
26:24.ꢀLOCALꢀchannelsꢀdoꢀnotꢀrespondꢀtoꢀtheꢀfaultꢀpins.
Forꢀ eachꢀ faultꢀ typeꢀ (overvoltageꢀ orꢀ overcurrent,ꢀ under-
voltage,ꢀ sequencingꢀ error,ꢀ andꢀ overtemperature),ꢀ eachꢀ
channel can be independently configured to respond in
theꢀrequiredꢀmannerꢀwithꢀtheꢀRESPONSEꢀbitsꢀinꢀMFR_
FAULT_RESPONSE.ꢀIfꢀchannelsꢀ0–11ꢀareꢀconfiguredꢀtoꢀ
latchꢀoffꢀforꢀaꢀparticularꢀfault,ꢀtheꢀchannelꢀturnsꢀoffꢀ(eitherꢀ
immediatelyꢀorꢀafterꢀtheꢀTOFF_DELAYꢀasꢀconfiguredꢀorꢀ
commanded)ꢀandꢀalsoꢀassertꢀoneꢀorꢀmoreꢀofꢀtheꢀFAULTn
pinsꢀifꢀtheyꢀareꢀenabledꢀwithꢀbitsꢀ18:16ꢀinꢀMFR_FAULT_
RESPONSE.ꢀTheꢀ channelꢀ remainsꢀ offꢀ andꢀ theꢀ FAULTn
outputs remain asserted until either the master power
controlꢀ isꢀ toggledꢀ usingꢀ theꢀ OPERATIONꢀ commandꢀ orꢀ
CONTROLnꢀpinsꢀasꢀconfiguredꢀinꢀtheꢀON_OFF_CONFIGꢀ
commandꢀorꢀtheꢀdeviceꢀisꢀresetꢀorꢀpowerꢀcycled.ꢀWhenꢀ
the device attempts to sequence the power supplies on,
all enabled faults must be cleared before the channel is
allowed to power-on or the FAULTn pins deasserted. If
channelsꢀ12–15ꢀareꢀconfiguredꢀtoꢀlatchꢀoff,ꢀtheyꢀrespondꢀ
likeꢀchannelsꢀ0–11;ꢀhowever,ꢀallꢀtheꢀpowerꢀsuppliesꢀmustꢀ
be turned off before they are allowed to turn back on.
GLOBAL Channels Respond to FAULTn Assertion
Bitsꢀ 26:24ꢀ inꢀ theꢀ MFR_FAULT_RESPONSEꢀ commandꢀ
areꢀ usedꢀ toꢀ configureꢀ GLOBALꢀ channelsꢀ toꢀ respondꢀ orꢀ
ignore one or more of the FAULTn pins when they are
asserted.ꢀ Whenꢀ oneꢀ orꢀ moreꢀ ofꢀ theꢀ enabledꢀ FAULTn
pinsꢀisꢀasserted,ꢀtheꢀchannelꢀeitherꢀdeassertsꢀtheꢀPSENnꢀ
outputꢀimmediatelyꢀorꢀafterꢀtheꢀTOFF_DELAYꢀaccordingꢀ
toꢀ theꢀ configurationꢀ ofꢀ bitꢀ 0ꢀ inꢀ theꢀ ON_OFF_CONFIGꢀ
command.ꢀTheꢀchannelꢀcontinuesꢀtoꢀdeassertꢀtheꢀPSENnꢀ
output until all enabled FAULTnꢀpinsꢀdeassert.ꢀWhenꢀallꢀ
enabled FAULTn pins deassert, the channel sequences
on as configured if no channel faults are present.
If the channel is configured to retry for a particular fault,
theꢀ channelꢀ turnsꢀ offꢀ (eitherꢀ immediatelyꢀ orꢀ afterꢀ theꢀ
TOFF_DELAYꢀ asꢀ configuredꢀ orꢀ commanded)ꢀ andꢀ alsoꢀ
assert one or more the FAULTn pins if they are enabled
withꢀbitsꢀ18:16ꢀinꢀMFR_FAULT_RESPONSE.ꢀTheꢀchan-
nel remains off and the FAULTn outputs remain asserted
forꢀtheꢀtimeꢀconfiguredꢀinꢀMFR_FAULT_RETRY.ꢀAfterꢀtheꢀ
timeꢀinꢀMFR_FAULT_RETRYꢀexpires,ꢀtheꢀdeviceꢀattemptsꢀ
to sequence the power supplies back on as long as all
the enabled faults in the channel are cleared. If all the
enabled faults are cleared, then the device deasserts
all the FAULTn pins it asserted and as long as no other
channels have asserted the FAULTn pins it has been
Temperature Fault Response
A temperature fault is declared when any of the enabled
temperature sensors detect a fault. A temperature fault
actsꢀgloballyꢀandꢀcanꢀaffectꢀallꢀofꢀtheꢀpowerꢀsupplies.ꢀForꢀ
all global supplies, the worst-case fault response of all
global channels is applied. If this response is latchoff or
retry, all FAULTn pins that are programmed to be asserted
by any of the global channels will be asserted. All local
channels respond independently, as programmed in that
channel’sꢀMFR_FAULT_RESPONSE.
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PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Fault Detection Before Power-On Sequencing
Logging Faults into MFR_NV_FAULT_LOG
Beforeꢀanyꢀpower-supplyꢀchannelꢀisꢀenabledꢀorꢀFAULTn
output deasserted, the device checks for overvoltage,
overcurrent,ꢀ andꢀ overtemperatureꢀ faultsꢀ (butꢀ notꢀ forꢀ
undervoltage)ꢀ ifꢀ theꢀ channelꢀ isꢀ configuredꢀ forꢀ aꢀ faultꢀ
responseꢀtoꢀeitherꢀlatchꢀoffꢀ(RESPONSE[1:0]ꢀ=ꢀ01)ꢀorꢀretryꢀ
(RESPONSE[1:0]ꢀ=ꢀ10)ꢀinꢀtheꢀMFR_FAULT_REPSONSEꢀ
command.ꢀ Undervoltageꢀ faultsꢀ areꢀ detectedꢀ whenꢀ theꢀ
power supply turns on and fails to reach the power-good
level,ꢀandꢀtheꢀTON_MAX_FAULT_LIMITꢀisꢀexceededꢀandꢀ
theꢀdeviceꢀtakesꢀfaultꢀactionꢀasꢀconfigured.ꢀSeeꢀTable 29.
Ifꢀ bitꢀ 15ꢀ ofꢀ MFR_FAULT_RESPONSEꢀ isꢀ set,ꢀ faultsꢀ areꢀ
logged into the on-board nonvolatile fault log for this
channel unless the response for the associated fault is con-
figuredꢀtoꢀtakeꢀnoꢀactionꢀ(RESPONSE[1:0]ꢀ=ꢀ00).ꢀToꢀkeepꢀ
from needlessly filling the fault log with excessive data, the
following rules are applied when subsequent faults occur.
Whenꢀ overvoltageꢀ faultsꢀ occurs,ꢀ subsequentꢀ overvoltageꢀ
faults on this channel are not written to the fault log until
eitherꢀtheꢀCLEAR_FAULTSꢀcommandꢀisꢀissuedꢀorꢀaꢀdeviceꢀ
reset occurs. The same rule applies to overcurrent, under-
voltage,ꢀ overtemperature,ꢀ andꢀ sequencingꢀ faultsꢀ (seeꢀ
Tableꢀ30 and Figureꢀ10).
Table 29. Fault Monitoring States
REQUIRED DEVICE CONFIGURATION
FOR ACTIVE MONITORING
FAULT
WHEN MONITORED
•ꢀ VoltageꢀMonitoringꢀEnabledꢀ
Overvoltage
Continuous monitoring
(SELECT[5:0]ꢀ=ꢀ10hꢀorꢀ20hꢀinꢀMFR_CHANNEL_CONFIG)
Stopꢀmonitoringꢀwhileꢀtheꢀpowerꢀsupplyꢀisꢀ
off;ꢀstartꢀmonitoringꢀwhenꢀvoltageꢀexceedsꢀ
theꢀPOWER_GOOD_ONꢀlevel
•ꢀ VoltageꢀMonitoringꢀEnabled
Undervoltage
(SELECT[5:0]ꢀ=ꢀ10hꢀorꢀ20hꢀinꢀMFR_CHANNEL_CONFIG)
•ꢀ CurrentꢀMonitoringꢀEnabled
Overcurrent
Continuous monitoring
(SELECT[5:0]ꢀ=ꢀ22hꢀinꢀMFR_CHANNEL_CONFIG)
•ꢀ SequencingꢀEnabled
Power-UpꢀTime
Overtemperature
Monitored only during power on sequence
Continuous monitoring
(SELECT[5:0]ꢀ=ꢀ10hꢀinꢀMFR_CHANNEL_CONFIG)
•ꢀ TemperatureꢀSensorꢀEnabled
(ENABLEꢀ=ꢀ1ꢀinꢀMFR_TEMP_SENSOR_CONFIG)
Note: Device response to faults is determined by the configuration of MFR_FAULT_RESPONSE.
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PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Table 30. MFR_FAULT_RESPONSE (D9h)
BIT
NAME
MEANING
31:27
0
Theseꢀbitsꢀalwaysꢀreturnꢀaꢀ0.
0ꢀ=ꢀFAULT2 response disabled
1ꢀ=ꢀFAULT2 response enabled
26
25
FAULT2_RESPONSE_ENABLE
FAULT1_RESPONSE_ENABLE
0ꢀ=ꢀFAULT1 response disabled
1ꢀ=ꢀFAULT1 response enabled
0ꢀ=ꢀFAULT0 response disabled
1ꢀ=ꢀFAULT0 response enabled
24
23:19
18
FAULT0_RESPONSE_ENABLE
0
Theseꢀbitsꢀalwaysꢀreturnꢀaꢀ0.
0ꢀ=ꢀFAULT2 assertion disabled
1ꢀ=ꢀFAULT2 assertion enabled
FAULT2_ASSERT_ENABLE
0ꢀ=ꢀFAULT1 assertion disabled
1ꢀ=ꢀFAULT1 assertion enabled
17
16
15
14
FAULT1_ASSERT_ENABLE
FAULT0_ASSERT_ENABLE
NV_LOG
0ꢀ=ꢀFAULT0 assertion disabled
1ꢀ=ꢀFAULT0 assertion enabled
0ꢀ=ꢀDoꢀnotꢀlogꢀtheꢀfaultꢀintoꢀMFR_NV_FAULT_LOG
1ꢀ=ꢀLogꢀtheꢀfaultꢀintoꢀMFR_NV_FAULT_LOG
0ꢀ=ꢀLOCALꢀ(affectꢀonlyꢀtheꢀselectedꢀpage)
1ꢀ=ꢀGLOBALꢀ(Noteꢀ1).
GLOBAL
Continuous excursion time before a fault or warning is
declaredꢀandꢀactionꢀisꢀtakenꢀ(Noteꢀ2).
00ꢀ=ꢀImmediate
01ꢀ=ꢀ2ms
13:12
FILTER[1:0]
10ꢀ=ꢀ3ms
11ꢀ=ꢀ4ms
11
10:8
7:6
0
Thisꢀbitꢀalwaysꢀreturnsꢀaꢀ0.
SeeꢀTableꢀ31.
ALARM_CONFIG[2:0]
OT_FAULT_LIMIT_RESPONSE[1:0]
SeeꢀTablesꢀ32ꢀandꢀ33ꢀ(Noteꢀ3).
TON_MAX_FAULT_LIMIT_RESPONSE[1:0]
(alsoꢀappliesꢀtoꢀMFR_TON_SEQ_MAX)
5:4
3:2
1:0
SeeꢀTablesꢀ32ꢀandꢀ33ꢀ(Notesꢀ4ꢀandꢀ5).ꢀ
SeeꢀTablesꢀ32ꢀandꢀ33ꢀ(Noteꢀ4).
SeeꢀTablesꢀ32ꢀandꢀ33ꢀ(Noteꢀ6).
VOUT_UV_FAULT_LIMIT_RESPONSE[1:0]
VOUT_OV_FAULT_LIMIT_RESPONSE[1:0]
IOUT_OC_FAULT_LIMIT_RESPONSE[1:0]
Note 1: ChannelsꢀconfiguredꢀtoꢀmonitorꢀcurrentꢀmustꢀbeꢀconfiguredꢀasꢀGLOBAL.ꢀAlsoꢀPAGESꢀ12–15ꢀmustꢀbeꢀconfiguredꢀasꢀGLOBAL.
Note 2:ꢀ TheꢀFILTERꢀselectionꢀdoesꢀnotꢀapplyꢀtoꢀtemperatureꢀorꢀsequencingꢀfaults.
Note 3:ꢀ AllꢀenabledꢀtemperatureꢀsensorꢀfaultsꢀareꢀlogicallyꢀORedꢀtogether.
Note 4: If the channel is configured to measure current, these bits are ignored.
Note 5:ꢀ TheseꢀbitsꢀareꢀignoredꢀforꢀPAGESꢀ12–15.
Note 6:ꢀ Dependsꢀonꢀwhetherꢀtheꢀchannelꢀisꢀconfiguredꢀtoꢀmonitorꢀvoltageꢀorꢀcurrent.
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
ALARM0–ALARM15
LOCAL0–LOCAL11
ALARM_CONFIG
FAULT2
FAULT1
FAULT0
MFR_FAULT_RETRY
MONITORING
16 CHANNELS
FAULT
RESPONSE
01 (LATCH OFF)
10 (RETRY)
OVERVOLTAGE
OVERCURRENT
OV/OC
UV
FILTER
11 (LOG ONLY)
GLOBAL/
LOCAL
SELECT
01 (LATCH OFF)
10 (RETRY)
FAULT0
16
16
LATCH
OFF
OR
UNDERVOLTAGE
FILTER
AND
AND
OR
11 (LOG ONLY)
RETRY
AND
NV
OR
01 (LATCH OFF)
10 (RETRY)
PWM7
GPO19
FAULT1
SEQUENCING
ERROR
OR
SEQ
OT
LOG
11 (LOG ONLY)
SELECT
SELECT
PWM7/
GPO19
01 (LATCH OFF)
10 (RETRY)
OVER-
TEMPERATURE
11 (LOG ONLY)
16
PSEN10
GPO10
FAULT2
AND
OR
INTERNAL
DS75LV
AND
PSEN10/
GPO10
DS75LV
DS75LV
DS75LV
OR
MFR_NV_FAULT_LOG
MFR_PWM_CONFIG
MFR_PSEN_CONFIG
MFR_FAULT_RESPONSE
BITS 13:12
BITS 10:8
BITS 7:0
BIT 15
BIT 14
BIT 16
BIT 17
BIT 18
NOTE: SIGNALS LISTED IN ITALICS ARE INTERNAL SIGNALS THAT CONNECT TO OTHER DEVICE FUNCTIONS.
SHADED BLOCKS ARE PMBus COMMANDS.
Figure 10. MFR_FAULT_RESPONSE Operation
Table 31. ALARM_CONFIG Codes
ALARM_CONFIG[2:0]
ALARM CONDITION
None
ALARM CRITERIA
000
001
010
011
100
101
110
111
—
Sequencingꢀfault
Faultꢀonly
Undervoltageꢀonly
Faultꢀonly
Undervoltageꢀonly
Faultꢀorꢀwarning
Faultꢀonly
Overvoltage/overcurrentꢀonly
Overvoltage/overcurrentꢀonly
Undervoltageꢀorꢀovervoltage/overcurrent
Undervoltageꢀorꢀovervoltage/overcurrent
Faultꢀorꢀwarning
Faultꢀonly
Faultꢀorꢀwarning
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PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Table 32. MFR_FAULT_RESPONSE Codes for GLOBAL Channels
RESPONSE[1:0]
FAULT RESPONSE
•ꢀ Setsꢀtheꢀcorrespondingꢀfaultꢀbitꢀinꢀtheꢀappropriateꢀstatusꢀregisterꢀ(Noteꢀ1).
•ꢀ LogsꢀfaultꢀintoꢀMFR_NV_FAULT_LOGꢀifꢀNV_LOGꢀ=ꢀ1.
•ꢀ Continues operation.
11
•ꢀ Asserts all enabled FAULTn outputs.
•ꢀ Setsꢀtheꢀcorrespondingꢀfaultꢀbitꢀinꢀtheꢀappropriateꢀstatusꢀregisterꢀ(Noteꢀ1).
•ꢀ LogsꢀfaultꢀintoꢀMFR_NV_FAULT_LOGꢀifꢀNV_LOGꢀ=ꢀ1.
•ꢀ WaitsꢀforꢀtheꢀtimeꢀconfiguredꢀinꢀMFR_FAULT_RETRYꢀandꢀthenꢀdeassertꢀtheꢀFAULTn outputs that were
assertedꢀifꢀfault-freeꢀ(Noteꢀ2).
10
(Retry)
•ꢀ Asserts all enabled FAULTn outputs.
•ꢀ Setsꢀtheꢀcorrespondingꢀfaultꢀbitꢀinꢀtheꢀappropriateꢀstatusꢀregisterꢀ(Noteꢀ1).
•ꢀ LogsꢀfaultꢀintoꢀMFR_NV_FAULT_LOGꢀifꢀNV_LOGꢀ=ꢀ1.
01
(Latchꢀoff)
•ꢀ Setsꢀtheꢀcorrespondingꢀfaultꢀbitꢀinꢀtheꢀappropriateꢀstatusꢀregisterꢀ(Noteꢀ1).
•ꢀ Continues operation without any action.
00
Note 1: ALERT is asserted if enabled when a new status bit is set. A status bit is latched when a particular fault occurs that causes
a fault response.
Note 2:ꢀ Fault-freeꢀdoesꢀnotꢀincludeꢀundervoltage.
Table 33. MFR_FAULT_RESPONSE Codes for LOCAL Channels
RESPONSE[1:0]
FAULT RESPONSE
•ꢀ Setsꢀtheꢀcorrespondingꢀfaultꢀbitꢀinꢀtheꢀappropriateꢀstatusꢀregisterꢀ(Noteꢀ1).
•ꢀ LogsꢀfaultꢀintoꢀMFR_NV_FAULT_LOGꢀifꢀNV_LOGꢀ=ꢀ1.
•ꢀ Continues operation.
11
•ꢀ ShutsꢀdownꢀtheꢀpowerꢀsupplyꢀbyꢀdeassertingꢀtheꢀPSENnꢀoutput.
10
(Retry)
•ꢀ Setsꢀtheꢀcorrespondingꢀfaultꢀbitꢀinꢀtheꢀappropriateꢀstatusꢀregisterꢀ(Noteꢀ1).
•ꢀ LogsꢀfaultꢀintoꢀMFR_NV_FAULT_LOGꢀifꢀNV_LOGꢀ=ꢀ1.
•ꢀ WaitsꢀforꢀtheꢀtimeꢀconfiguredꢀinꢀMFR_FAULT_RETRYꢀandꢀrestartsꢀtheꢀsupplyꢀifꢀfault-freeꢀ(Noteꢀ2).
•ꢀ LatchesꢀoffꢀtheꢀpowerꢀsupplyꢀbyꢀdeassertingꢀtheꢀPSENnꢀoutput.
•ꢀ Setsꢀtheꢀcorrespondingꢀfaultꢀbitꢀinꢀtheꢀappropriateꢀstatusꢀregisterꢀ(Noteꢀ1).
•ꢀ LogsꢀfaultꢀintoꢀMFR_NV_FAULT_LOGꢀifꢀNV_LOGꢀ=ꢀ1.
01
(Latchꢀoff)
•ꢀ Setsꢀtheꢀcorrespondingꢀfaultꢀbitꢀinꢀtheꢀappropriateꢀstatusꢀregisterꢀ(Noteꢀ1).
•ꢀ Continues operation without any action.
00
Note 1: ALERT is asserted if enabled when a new status bit is set. A status bit is latched when a particular fault occurs that causes
a fault response.
Note 2:ꢀ Fault-freeꢀdoesꢀnotꢀincludeꢀundervoltage.
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PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Alarm Output Functionality
MFR_NV_FAULT_LOG (DCh)
Anyꢀ ofꢀ theꢀ GPOnꢀ pinsꢀ canꢀ beꢀ configuredꢀ toꢀ outputꢀ
theꢀ alarmꢀ signals.ꢀ Seeꢀ theꢀ MFR_PWM_CONFIGꢀ andꢀ
MFR_PSEN_CONFIGꢀ commandsꢀ forꢀ details.ꢀ Whenꢀ anꢀ
undervoltageꢀ orꢀ overvoltage/overcurrentꢀ alarmꢀ isꢀ occurr
ing, the output remains asserted as long as the alarm
continues.ꢀ Whenꢀ aꢀ sequencingꢀ faultꢀ occurs,ꢀ theꢀ alarmꢀ
pinꢀ remainsꢀ assertedꢀ untilꢀ eitherꢀ aꢀ CLEAR_FAULTSꢀ
command is received, or a master power control off input
isꢀreceivedꢀwithꢀeitherꢀtheꢀOPERATIONꢀcommandꢀorꢀtheꢀ
CONTROLnꢀpins.
Dataꢀfromꢀeachꢀofꢀtheꢀ15ꢀnonvolatileꢀfaultꢀlogsꢀisꢀconsti-
tutedꢀ (inꢀ nonvolatileꢀ memory)ꢀ asꢀ aꢀ blockꢀ ofꢀ 255ꢀ bytes.ꢀ
Executingꢀ theꢀ MFR_NV_FAULT_LOGꢀ commandꢀ usingꢀ
theꢀ Readꢀ 32ꢀ SMBusꢀ protocol,ꢀ eachꢀ blockꢀ ofꢀ 255ꢀ bytesꢀ
can be read back from the device in packets of 4 bytes.
Alternatively,ꢀ theꢀ MFR_NV_FAULT_LOGꢀ canꢀ alsoꢀ beꢀ
executed to read back a block of 255 bytes by using
theꢀ Blockꢀ Readꢀ SMBusꢀ protocolꢀ exceptꢀ thatꢀ theꢀ deviceꢀ
doesꢀ notꢀ reportꢀ theꢀ Byteꢀ Countꢀ duringꢀ readꢀ back.ꢀ Theꢀ
MFR_NV_FAULT_LOGꢀ commandꢀ mustꢀ beꢀ executedꢀ 15ꢀ
times to dump the complete nonvolatile fault log. If the
returnedꢀfaultꢀlogꢀisꢀallꢀFFsꢀ(exceptꢀbytesꢀ0ꢀandꢀ1),ꢀthisꢀ
indicates that this fault log has not been written by the
device. As the device is operating, it is reading the latest
operating conditions for voltage, current, and temperature
and updating the status registers. All this information
isꢀstoredꢀinꢀon-boardꢀRAM.ꢀWhenꢀaꢀfaultꢀisꢀdetectedꢀ(ifꢀ
soꢀ enabledꢀ inꢀ MFR_FAULT_RESPONSE),ꢀ theꢀ deviceꢀ
automatically logs this information to one of the 15
nonvolatile fault logs. After 15 faults have been
written,ꢀbitꢀ0ꢀofꢀSTATUS_CMLꢀisꢀsetꢀandꢀtheꢀdeviceꢀcanꢀ
beꢀ configuredꢀ (withꢀ theꢀ NV_LOG_OVERWRITEꢀ bitꢀ inꢀ
MFR_NV_LOG_CONFIG)ꢀtoꢀeitherꢀstopꢀwritingꢀadditionalꢀ
fault logs or write over the oldest data. The host can clear
theꢀfaultꢀlogꢀbyꢀsettingꢀtheꢀCLEAR_NV_FAULT_LOGꢀbitꢀinꢀ
MFR_NV_LOG_CONFIG.ꢀIfꢀaꢀpowerꢀsupplyꢀisꢀnotꢀenabledꢀ
to measure voltage, current, or if a temperature sensor is
disabled,ꢀtheꢀassociatedꢀfaultꢀlogꢀpositionꢀreturnsꢀ0000hꢀ
(seeꢀFigureꢀ11).
MFR_FAULT_RETRY (DAh)
TheꢀMFR_FAULT_RETRYꢀcommandꢀsetsꢀtheꢀdelayꢀtimeꢀ
between channel shutdown due to fault event and its
restarting if the fault response is configured to retry. This
command value is used for all fault responses.
The retry timer starts when the fault occurs. If the faulty
channelꢀhasꢀbeenꢀconfiguredꢀtoꢀassertꢀoneꢀorꢀmoreꢀFAULTꢀ
pins,ꢀtheꢀFAULTꢀpinsꢀareꢀasserted.ꢀForꢀanꢀundervoltageꢀ
fault happening on a channel configured for sequencing
(MFR_CHANNEL_CONFIGꢀ[5:0]=ꢀ10h),ꢀtheꢀFAULTꢀpin(s)ꢀ
deasserts immediately when the retry timer expires.
If the channel is configured for voltage monitoring
(MFR_CHANNEL_CONFIGꢀ [5:0]=ꢀ 20h)ꢀ theꢀ FAULTꢀ pinꢀ
deasserts when the retry timer expires if no fault con-
ditionꢀ isꢀ present.ꢀ Forꢀ allꢀ otherꢀ faultꢀ events,ꢀ theꢀ FAULTꢀ
pin(s)ꢀ deassertsꢀ whenꢀ retryꢀ timerꢀ expiresꢀ ifꢀ noꢀ faultꢀ isꢀ
present.
MFR_FAULT_RETRYꢀshouldꢀbeꢀconfiguredꢀwithꢀaꢀvalueꢀ
largerꢀthanꢀtheꢀlargestꢀsystemꢀTOFF_DELAY.ꢀTheꢀ2ꢀdataꢀ
bytesꢀareꢀinꢀDIRECTꢀformat.
FLASH
RAM
EACH FAULT IS WRITTEN
INTO THE NEXT FAULT LOG
EACH COMMAND READ
FAULT LOG INDEX 0
ACCESSES THE NEXT FAULT LOG
(255 BYTES)
FAULT_LOG_INDEX
FAULT_LOG_COUNT
MFR_TIME_COUNT
STATUS_WORD
FAULT LOG INDEX 1
(255 BYTES)
STATUS_VOUT/STATUS_IOUT
STATUS_MFR_SPECIFIC
FAULT
OCCURRENCE
STATUS_CML
MFR_NV_FAULT_LOG
FAULT LOG INDEX 2
STATUS_TEMPERATURE
READ_VOUT/READ_IOUT (3 READINGS)
READ_TEMPERATURE_1
MFR_VOUT_PEAK/MFR_IOUT_PEAK
MFR_TEMPERATURE_PEAK
MFR_VOUT_MIN
(255 BYTES)
FAULT LOG INDEX 14
(255 BYTES)
Figure 11. MFR_NV_FAULT_LOG
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
ThereꢀisꢀaꢀFAULT_LOG_COUNTꢀ(16-bitꢀcounter)ꢀatꢀtheꢀ
beginning of each fault log that indicates which fault log
is the latest. This counter rolls over should more than
65,535 faults be logged. This counter is not cleared when
theꢀ CLEAR_NV_FAULT_LOGꢀ bitꢀ inꢀ MFR_NV_LOG_
CONFIGꢀisꢀtoggled.ꢀTheꢀ255ꢀbytesꢀreturnedꢀbyꢀtheꢀMFR_
NV_FAULT_LOGꢀcommandꢀareꢀdescribedꢀinꢀTable 34.
If an error occurs while the device is attempting to write to
orꢀclearꢀtheꢀMFR_NV_FAULT_LOG,ꢀtheꢀdeviceꢀsetsꢀtheꢀ
CMLꢀbitꢀinꢀSTATUS_WORDꢀ(noꢀbitsꢀareꢀsetꢀinꢀSTATUS_
CML)ꢀandꢀALERTꢀisꢀassertedꢀ(ifꢀenabledꢀinꢀMFR_MODE).
USER NOTE: V
must be above 2.9V for the device to
DD
clearꢀorꢀlogꢀdataꢀintoꢀMFR_NV_FAULT_LOG.
Table 34. MFR_NV_FAULT_LOG (DCh)
BYTE
0
PARAMETER
00h/FAULT_LOG_INDEX
BYTE
128
130
132
134
136
138
140
142
144
146
148
150
152
154
156
158
160
162
164
166
168
170
172
174
176
178
180
182
184
186
PARAMETER
READ_VOUT/READ_IOUTꢀT1ꢀPAGEꢀ11
READ_VOUT/READ_IOUTꢀT2ꢀPAGEꢀ11
READ_VOUT/READ_IOUTꢀT0ꢀPAGEꢀ12
READ_VOUT/READ_IOUTꢀT1ꢀPAGEꢀ12
READ_VOUT/READ_IOUTꢀT2ꢀPAGEꢀ12
READ_VOUT/READ_IOUTꢀT0ꢀPAGEꢀ13
READ_VOUT/READ_IOUTꢀT1ꢀPAGEꢀ13
READ_VOUT/READ_IOUTꢀT2ꢀPAGEꢀ13
READ_VOUT/READ_IOUTꢀT0ꢀPAGEꢀ14
READ_VOUT/READ_IOUTꢀT1ꢀPAGEꢀ14
READ_VOUT/READ_IOUTꢀT2ꢀPAGEꢀ14
READ_VOUT/READ_IOUTꢀT0ꢀPAGEꢀ15
READ_VOUT/READ_IOUTꢀT1ꢀPAGEꢀ15
READ_VOUT/READ_IOUTꢀT2ꢀPAGEꢀ15
0000h
2
FAULT_LOG_COUNT
4
MFR_TIME_COUNTꢀ(LSW)
6
MFR_TIME_COUNTꢀ(MSW)
8
0000h
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
40
42
44
46
48
50
52
54
56
58
STATUS_CML/00h
STATUS_WORD
STATUS_VOUT/STATUS_IOUTꢀPAGESꢀ0/1
STATUS_VOUT/STATUS_IOUTꢀPAGESꢀ2/3
STATUS_VOUT/STATUS_IOUTꢀPAGESꢀ4/5
STATUS_VOUT/STATUS_IOUTꢀPAGESꢀ6/7
STATUS_VOUT/STATUS_IOUTꢀPAGESꢀ8/9
STATUS_VOUT/STATUS_IOUTꢀPAGESꢀ10/11
STATUS_VOUT/STATUS_IOUTꢀPAGESꢀ12/13
STATUS_VOUT/STATUS_IOUTꢀPAGESꢀ14/15
STATUS_MFR_SPECIFICꢀPAGESꢀ0/1
STATUS_MFR_SPECIFICꢀPAGESꢀ2/3
STATUS_MFR_SPECIFICꢀPAGESꢀ4/5
STATUS_MFR_SPECIFICꢀPAGESꢀ6/7
STATUS_MFR_SPECIFICꢀPAGESꢀ8/9
STATUS_MFR_SPECIFICꢀPAGESꢀ10/11
STATUS_MFR_SPECIFICꢀPAGESꢀ12/13
STATUS_MFR_SPECIFICꢀPAGESꢀ14/15
STATUS_MFR_SPECIFICꢀPAGEꢀ255/00h
STATUS_TEMPERATUREꢀPAGESꢀ16/17
STATUS_TEMPERATUREꢀPAGESꢀ18/19
STATUS_TEMPERATUREꢀPAGEꢀ20/00h
CURRENT_CHANNELSꢀ(Noteꢀ4)
0000h
0000h
0000h
0000h
MFR_VOUT_PEAK/MFR_IOUT_PEAKꢀPAGEꢀ0
MFR_VOUT_PEAK/MFR_IOUT_PEAKꢀPAGEꢀ1
MFR_VOUT_PEAK/MFR_IOUT_PEAKꢀPAGEꢀ2
MFR_VOUT_PEAK/MFR_IOUT_PEAKꢀPAGEꢀ3
MFR_VOUT_PEAK/MFR_IOUT_PEAKꢀPAGEꢀ4
MFR_VOUT_PEAK/MFR_IOUT_PEAKꢀPAGEꢀ5
MFR_VOUT_PEAK/MFR_IOUT_PEAKꢀPAGEꢀ6
MFR_VOUT_PEAK/MFR_IOUT_PEAKꢀPAGEꢀ7
MFR_VOUT_PEAK/MFR_IOUT_PEAKꢀPAGEꢀ8
MFR_VOUT_PEAK/MFR_IOUT_PEAKꢀPAGEꢀ9
MFR_VOUT_PEAK/MFR_IOUT_PEAKꢀPAGEꢀ10
MFR_VOUT_PEAK/MFR_IOUT_PEAKꢀPAGEꢀ11
0000h
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Table 34. MFR_NV_FAULT_LOG (DCh) (continued)
BYTE
60
PARAMETER
BYTE
188
190
192
194
196
198
200
202
204
206
208
210
212
214
216
218
220
222
224
226
228
230
232
234
236
238
240
242
244
246
248
250
252
254
PARAMETER
MFR_VOUT_PEAK/MFR_IOUT_PEAKꢀPAGEꢀ12
MFR_VOUT_PEAK/MFR_IOUT_PEAKꢀPAGEꢀ13
MFR_VOUT_PEAK/MFR_IOUT_PEAKꢀPAGEꢀ14
MFR_VOUT_PEAK/MFR_IOUT_PEAKꢀPAGEꢀ15
MFR_VOUT_MINꢀPAGEꢀ0
READ_VOUT/READ_IOUTꢀT0ꢀPAGEꢀ0ꢀ(Notesꢀ2,ꢀ3)
READ_VOUT/READ_IOUTꢀT1ꢀPAGEꢀ0ꢀ(Notesꢀ2,ꢀ3)
READ_VOUT/READ_IOUTꢀT2ꢀPAGEꢀ0ꢀ(Notesꢀ2,ꢀ3)
READ_VOUT/READ_IOUTꢀT0ꢀPAGEꢀ1
READ_VOUT/READ_IOUTꢀT1ꢀPAGEꢀ1
READ_VOUT/READ_IOUTꢀT2ꢀPAGEꢀ1
READ_VOUT/READ_IOUTꢀT0ꢀPAGEꢀ2
READ_VOUT/READ_IOUTꢀT1ꢀPAGEꢀ2
READ_VOUT/READ_IOUTꢀT2ꢀPAGEꢀ2
READ_VOUT/READ_IOUTꢀT0ꢀPAGEꢀ3
READ_VOUT/READ_IOUTꢀT1ꢀPAGEꢀ3
READ_VOUT/READ_IOUTꢀT2ꢀPAGEꢀ3
READ_VOUT/READ_IOUTꢀT0ꢀPAGEꢀ4
READ_VOUT/READ_IOUTꢀT1ꢀPAGEꢀ4
READ_VOUT/READ_IOUTꢀT2ꢀPAGEꢀ4
READ_VOUT/READ_IOUTꢀT0ꢀPAGEꢀ5
READ_VOUT/READ_IOUTꢀT1ꢀPAGEꢀ5
READ_VOUT/READ_IOUTꢀT2ꢀPAGEꢀ5
READ_VOUT/READ_IOUTꢀT0ꢀPAGEꢀ6
READ_VOUT/READ_IOUTꢀT1ꢀPAGEꢀ6
READ_VOUT/READ_IOUTꢀT2ꢀPAGEꢀ6
READ_VOUT/READ_IOUTꢀT0ꢀPAGEꢀ7
READ_VOUT/READ_IOUTꢀT1ꢀPAGEꢀ7
READ_VOUT/READ_IOUTꢀT2ꢀPAGEꢀ7
READ_VOUT/READ_IOUTꢀT0ꢀPAGEꢀ8
READ_VOUT/READ_IOUTꢀT1ꢀPAGEꢀ8
READ_VOUT/READ_IOUTꢀT2ꢀPAGEꢀ8
READ_VOUT/READ_IOUTꢀT0ꢀPAGEꢀ9
READ_VOUT/READ_IOUTꢀT1ꢀPAGEꢀ9
READ_VOUT/READ_IOUTꢀT2ꢀPAGEꢀ9
READ_VOUT/READ_IOUTꢀT0ꢀPAGEꢀ10
READ_VOUT/READ_IOUTꢀT1ꢀPAGEꢀ10
READ_VOUT/READ_IOUTꢀT2ꢀPAGEꢀ10
READ_VOUT/READ_IOUTꢀT0ꢀPAGEꢀ11
62
64
66
68
70
MFR_VOUT_MINꢀPAGEꢀ1
72
MFR_VOUT_MINꢀPAGEꢀ2
74
MFR_VOUT_MINꢀPAGEꢀ3
76
MFR_VOUT_MINꢀPAGEꢀ4
78
MFR_VOUT_MINꢀPAGEꢀ5
80
MFR_VOUT_MINꢀPAGEꢀ6
82
MFR_VOUT_MINꢀPAGEꢀ7
84
MFR_VOUT_MINꢀPAGEꢀ8
86
MFR_VOUT_MINꢀPAGEꢀ9
88
MFR_VOUT_MINꢀPAGEꢀ10
90
MFR_VOUT_MINꢀPAGEꢀ11
92
MFR_VOUT_MINꢀPAGEꢀ12
94
MFR_VOUT_MINꢀPAGEꢀ13
96
MFR_VOUT_MINꢀPAGEꢀ14
98
MFR_VOUT_MINꢀPAGEꢀ15
100
102
104
106
108
110
112
114
116
118
120
122
124
126
0000h
0000h
READ_TEMPERATURE_1ꢀPAGEꢀ16
READ_TEMPERATURE_1ꢀPAGEꢀ17
READ_TEMPERATURE_1ꢀPAGEꢀ18
READ_TEMPERATURE_1ꢀPAGEꢀ19
READ_TEMPERATURE_1ꢀPAGEꢀ20
MFR_TEMPERATURE_PEAKꢀPAGEꢀ16
MFR_TEMPERATURE_PEAKꢀPAGEꢀ17
MFR_TEMPERATURE_PEAKꢀPAGEꢀ18
MFR_TEMPERATURE_PEAKꢀPAGEꢀ19
MFR_TEMPERATURE_PEAKꢀPAGEꢀ20
0000h
LOG_VALIDꢀ(Noteꢀ1)
Note 1:ꢀ LOG_VALIDꢀisꢀsetꢀtoꢀDDhꢀifꢀtheꢀfaultꢀlogꢀcontainsꢀvalidꢀdata.
Note 2:ꢀ ForꢀREAD_VOUT,ꢀREAD_IOUT,ꢀT2ꢀisꢀtheꢀoldestꢀreadingꢀandꢀT0ꢀisꢀtheꢀnewestꢀreading.
Note 3:ꢀ STATUS_VOUT/STATUS_IOUTꢀandꢀREAD_VOUT/STATUS_IOUTꢀdependꢀonꢀwhetherꢀtheꢀchannelꢀisꢀconfiguredꢀtoꢀmonitorꢀ
voltage or current.
Note 4:ꢀ CURRENT_CHANNELSꢀisꢀaꢀbitmaskꢀ(0ꢀ=ꢀvoltage/1ꢀ=ꢀcurrent)ꢀindicatingꢀwhichꢀchannelsꢀareꢀenabledꢀforꢀcurrentꢀmeasurement.
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●ꢀ Readꢀcurrentꢀonly;ꢀdoꢀnotꢀmonitorꢀforꢀcurrentꢀfaultsꢀorꢀ
warningsꢀ(SELECT[5:0]ꢀ=ꢀ23h)
MFR_TIME_COUNT (DDh)
Theꢀ MFR_TIME_COUNTꢀ commandꢀ returnsꢀ theꢀ currentꢀ
value of a real-time counter that increments every 5ms,
20ms,ꢀ 80ms,ꢀ orꢀ 160msꢀ dependingꢀ onꢀ theꢀ configurationꢀ
ofꢀtheꢀNV_LOG_DEPTHꢀbitsꢀinꢀMFR_NV_LOG_CONFIG.ꢀ
This counter is useful in determining the time between
multiple faults. The counter is a 32-bit value that rolls
over.ꢀTheꢀcountꢀisꢀresetꢀtoꢀzeroꢀuponꢀdeviceꢀpowerꢀcycleꢀ
or RSTꢀaction,ꢀorꢀaꢀsoft-reset.ꢀMFR_TIME_COUNTꢀcanꢀ
be preset to any value and starts counting up from the
preset value.
●ꢀ General-purposeꢀinputꢀ(GPI);ꢀactiveꢀlowꢀ(SELECT[5:0]ꢀ
=ꢀ30h)
●ꢀ General-purposeꢀinputꢀ(GPI);ꢀactiveꢀhighꢀꢀ(SELECT[5:0]ꢀ
=ꢀ34h)
●ꢀ Inputꢀisꢀdisabledꢀ(SELECT[5:0]ꢀ=ꢀ00h)
If the monitoring channel is configured to monitor volt-
ageꢀ forꢀ sequencingꢀ (SELECT[5:0]ꢀ =ꢀ 10h),ꢀ thenꢀ theꢀ
associatedꢀ PSENnꢀ outputꢀ channelꢀ mustꢀ alsoꢀ beꢀ config-
uredꢀforꢀcontrollingꢀpowerꢀsuppliesꢀbyꢀsettingꢀtheꢀSELECTꢀ
bitsꢀ inꢀ MFR_PSEN_CONFIGꢀ toꢀ 000.ꢀ Seeꢀ theꢀ MFR_
PSEN_CONFIGꢀcommandꢀdescriptionꢀforꢀmoreꢀdetails.
MFR_CHANNEL_CONFIG (E4h)
Theꢀ MFR_CHANNEL_CONFIGꢀ commandꢀ isꢀ usedꢀ toꢀ
configureꢀ theꢀ monitoringꢀ channelsꢀ (PAGESꢀ 0–15).ꢀ
This command should not be changed while the power
suppliesꢀ areꢀ operating.ꢀ Theꢀ MFR_CHANNEL_CONFIGꢀ
command is described in Table 35 and shown in Figureꢀ12.
Whenꢀ theꢀ RSn/GPInꢀ pinsꢀ areꢀ configuredꢀ asꢀ general-
purposeꢀ inputsꢀ (GPIs)ꢀ theꢀ READ_VOUTꢀ commandꢀ
reportsꢀ0000hꢀwhenꢀtheꢀpinꢀisꢀinactiveꢀandꢀ0001hꢀwhenꢀ
the pin is active.
Eachꢀ RSn/GPInꢀ pinꢀ canꢀ beꢀ independentlyꢀ configuredꢀ
usingꢀtheꢀSELECT[5:0]ꢀbitsꢀtoꢀoneꢀofꢀtheꢀfollowing:
Also,ꢀ whenꢀ theꢀ RSn/GPInꢀ pinsꢀ areꢀ configuredꢀ toꢀ
monitorꢀvoltageꢀ(SELECT[5:0]ꢀ=ꢀ10hꢀorꢀ20h)ꢀorꢀactꢀasꢀ
GPIꢀ(SELECT[5:0]ꢀ=ꢀ30hꢀorꢀ34h),ꢀeachꢀchannelꢀcanꢀbeꢀ
independently configured to generate a signature signal
at the SEQ output. This would facilitate event-based
sequencingꢀ(inꢀmultipleꢀdeviceꢀsystems),ꢀbyꢀindicatingꢀthatꢀ
thisꢀ powerꢀ supplyꢀ hasꢀ reachedꢀ itsꢀ POWER_GOOD_ONꢀ
level and other channels can now proceed with their
power-up.
●ꢀ Monitorꢀ voltage;ꢀ useꢀ theꢀ monitoredꢀ voltageꢀ forꢀ
sequencingꢀ(SELECT[5:0]ꢀ=ꢀ10h)
●ꢀ Monitorꢀ voltage;ꢀ doꢀ notꢀ useꢀ forꢀ sequencingꢀ
(SELECT[5:0]ꢀ=ꢀ20h)
●ꢀ Monitorꢀcurrentꢀ(SELECT[5:0]ꢀ=ꢀ22h)
●ꢀ Readꢀvoltageꢀonly;ꢀdoꢀnotꢀmonitorꢀforꢀvoltageꢀfaultsꢀorꢀ
warningsꢀ(SELECT[5:0]ꢀ=ꢀ21h)
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Table 35. MFR_CHANNEL_CONFIG (E4h)
BIT
NAME
MEANING
15:12
0
Theseꢀbitsꢀalwaysꢀreturnꢀaꢀ0.
These bits determine which SEQ signature the channel should generate after crossing the
POWER_GOOD_ONꢀlevel:
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
0000ꢀ
0001ꢀ
0010ꢀ
0011ꢀ
0100ꢀ
0101ꢀ
0110ꢀ
0111ꢀ
Disabledꢀ
1000ꢀ
1001ꢀ
1010ꢀ
1011ꢀ
1100ꢀ
1101ꢀ
1110ꢀ
1111ꢀꢀ
Signatureꢀ8
Signatureꢀ9
Signatureꢀ10
Signatureꢀ11
Signatureꢀ12
Signatureꢀ13
Signatureꢀ14
Signatureꢀ15
Signatureꢀ1ꢀ
Signatureꢀ2ꢀ
Signatureꢀ3ꢀ
Signatureꢀ4ꢀ
Signatureꢀ5ꢀ
Signatureꢀ6ꢀ
Signatureꢀ7ꢀ
11:8
SEQ_GENERATE
7:6
0
Theseꢀbitsꢀalwaysꢀreturnꢀaꢀ0.
TheseꢀbitsꢀselectꢀtheꢀfunctionꢀofꢀtheꢀRSn/GPInꢀpins:
SELECT[5:0]
010000ꢀ(10h)ꢀ
100000ꢀ(20h)ꢀ
100010ꢀ(22h)ꢀ
100001ꢀ(21h)ꢀ
100011ꢀ(23h)ꢀ
110000ꢀ(30h)ꢀ
110100ꢀ(34h)ꢀ
000000ꢀ(00h)ꢀ
SELECTEDꢀCHANNELꢀFUNCTION
Sequencingꢀ+ꢀvoltageꢀmonitoringꢀ(onlyꢀvalidꢀforꢀPAGESꢀ0–11)*
Voltageꢀmonitoringꢀ(noꢀsequencing)
Currentꢀmonitoring
Voltageꢀreadꢀonly
Currentꢀreadꢀonly
General-purposeꢀinputꢀactiveꢀlow
General-purposeꢀinputꢀactiveꢀhigh
Disabled
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
5:0
SELECT[5:0]
*For proper sequencing, the SELECT bits in MFR_PSEN_CONFIG must be set to 000.
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SEQ
PSEN11
GPO11
SEQ
16
OR
SELECT
PSEN11/GPO11
MFR_PSEN_CONFIG
SEQ GENERATE
POWER_GOOD_ON
PG0–PG15
POWER_GOOD_OFF
VOUT_OV_FAULT_LIMIT
VOUT_OV_WARN_LIMIT
VOUT_UV_FAULT_LIMIT
VOUT_UV_WARN_LIMIT
VOUT_SCALE_MONITOR
MFR_FAULT_RESPONSE
READ_VOUT
IOUT_OC_FAULT_LIMIT
IOUT_OC_WARN_LIMIT
IOUT_CAL_GAIN
MFR_FAULT_RESPONSE
VOLTAGE MONITOR
SELECT = 10h or 20h
READ_IOUT
CURRENT MONITOR
SELECT = 22h
VOLTAGE READ-ONLY
SELECT = 21h
VOUT_SCALE_MONITOR
IOUT_CAL_GAIN
READ_VOUT
READ_IOUT
RS0–RS15
GPI0–GPI15
CURRENT READ-ONLY
SELECT = 23h
LOGIC LEVEL
(ACTIVE HIGH/LOW)
GENERAL-PURPOSE INPUT
SELECT = 30h or 34h
GPI0–GPI15
READ_VOUT
DISABLED
SELECT = 00h
0000h WHEN INACTIVE
0001h WHEN ACTIVE
MFR_CHANNEL_CONFIG
BITS 5:0
BITS 11:8
NOTE: SIGNALS LISTED IN ITALICS ARE INTERNAL SIGNALS THAT CONNECT TO OTHER DEVICE FUNCTIONS.
SHADED BLOCKS ARE PMBUS COMMAND
Figure 12. MFR_CHANNEL_CONFIG Command
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Table 36. Fault-Monitoring States
REQUIRED DEVICE CONFIGURATION
FOR ACTIVE MONITORING
FAULT
WHEN MONITORED
•ꢀ Voltage monitoring enabled
(SELECT[5:0]ꢀ=ꢀ10hꢀorꢀ20hꢀinꢀMFR_CHANNEL_CONFIG)
Overvoltage
Continuous monitoring.
•ꢀ IfꢀSELECT[5:0]ꢀ=ꢀ10hꢀ(monitorꢀandꢀ
sequenceꢀmode),ꢀstopsꢀmonitoringꢀwhenꢀ
PSENꢀisꢀdisabled.ꢀPowerꢀGoodꢀstartsꢀ
monitoringꢀwhenꢀPSENꢀisꢀenabledꢀandꢀ
Undervoltageꢀmonitoringꢀstartsꢀwhenꢀvoltageꢀ
exceedsꢀtheꢀPOWER_GOOD_ONꢀlevel.ꢀꢀꢀꢀ
•ꢀ IfꢀSELECT[5:0]ꢀ=ꢀ20hꢀ(monitorꢀonlyꢀmode),ꢀ
starts monitoring when the voltage exceeds
theꢀPOWER_GOOD_ONꢀlevel.
Undervoltage/
PowerꢀGood
•ꢀ Voltage monitoring enabled
(SELECT[5:0]ꢀ=ꢀ10hꢀorꢀ20hꢀinꢀMFR_CHANNEL_CONFIG)
•ꢀ Current monitoring enabled
(SELECT[5:0]ꢀ=ꢀ22hꢀinꢀMFR_CHANNEL_CONFIG)
Overcurrent
Power-UpꢀTime
Overtemperature
Continuous monitoring.
•ꢀ Sequencingꢀenabled
(SELECT[5:0]ꢀ=ꢀ10hꢀinꢀMFR_CHANNEL_CONFIG)
Monitored only during power-on sequence.
Continuous monitoring.
•ꢀ Temperature sensor enabled
(ENABLEꢀ=ꢀ1ꢀinꢀMFR_TEMP_SENSOR_CONFIG)
Note: Device response to faults is determined by the configuration of MFR_FAULT_RESPONSE.
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●ꢀ Forceꢀpinꢀassertionꢀ(SELECT[2:0]ꢀ=ꢀ001)
●ꢀ Forceꢀpinꢀdeassertionꢀ(SELECT[2:0]ꢀ=ꢀ010)
MFR_TON_SEQ_MAX (E6h)
Theꢀ MFR_TON_SEQ_MAXꢀ commandꢀ setsꢀ anꢀ upperꢀ
limit,ꢀ inꢀ milliseconds,ꢀ fromꢀ aꢀ sequencingꢀ groupꢀ (eitherꢀ
SEQUENCE0ꢀorꢀSEQUENCE1,ꢀasꢀchosenꢀbyꢀtheꢀSEQ_
SELECTꢀbitꢀinꢀtheꢀMFR_SEQ_CONFIGꢀcommand),ꢀiniti-
ating the power-up sequence until the channel expects
to begin its power-up based on an event, which could be
eitherꢀaꢀlogicꢀcombinationꢀofꢀpower-goodꢀ(PG)ꢀandꢀGPIꢀ
signals or a match on the SEQ pin, as configured with the
SELECTꢀ bitsꢀ inꢀ MFR_SEQ_CONFIG.ꢀTheꢀ 2ꢀ dataꢀ bytesꢀ
areꢀinꢀDIRECTꢀformat.ꢀIfꢀthisꢀvalueꢀisꢀzero,ꢀthenꢀtheꢀlimitꢀisꢀ
disabled.ꢀInꢀresponseꢀtoꢀtheꢀMFR_TON_SEQ_MAXꢀbeingꢀ
exceeded,ꢀtheꢀdeviceꢀdoesꢀtheꢀfollowing:
●ꢀ Assertꢀwhenꢀallꢀenabledꢀchannelꢀpower-goodꢀ(PG)ꢀorꢀ
GPIꢀareꢀassertedꢀ(SELECT[2:0]ꢀ=ꢀ011)
●ꢀ Assertꢀ whenꢀ anyꢀ enabledꢀ alarmꢀ goesꢀ activeꢀ
(SELECT[2:0]ꢀ=ꢀ100)
Also,ꢀeachꢀPWMn/GPOnꢀpinꢀcanꢀbeꢀindependentlyꢀconfig-
ured to be active high or active low and either push-pull or
openꢀdrainꢀusingꢀtheꢀHI_LOꢀandꢀPP_ODꢀbits,ꢀrespectively.
IfꢀSELECT[2:0]ꢀ=ꢀ011,ꢀtheꢀPWMn/GPOnꢀoutputꢀisꢀconfig-
ured to assert when some combination of power-goods
(PGs)ꢀ andꢀ GPIsꢀ fromꢀ eachꢀ channelꢀ areꢀ asserted.ꢀ Theꢀ
channels that should be used in this combination are
selectedꢀ usingꢀ theꢀ PG_GPI_SELECTꢀ bitsꢀ 31:16.ꢀ Ifꢀ theꢀ
PG_GPI_SELECTꢀ bitꢀ isꢀ cleared,ꢀ thenꢀ theꢀ associatedꢀ
channel is not used in the logical combination to assert the
GPOꢀoutput.ꢀIfꢀtheꢀPG_GPI_SELECTꢀbitꢀisꢀset,ꢀthenꢀtheꢀPGꢀ
orꢀGPIꢀfromꢀthatꢀchannelꢀisꢀusedꢀinꢀtheꢀlogicalꢀcombinationꢀtoꢀ
assertꢀorꢀdeassertꢀtheꢀGPOnꢀoutput.ꢀThisꢀfunctionꢀisꢀusefulꢀinꢀ
creating system power-good signals.
1)ꢀ SetsꢀtheꢀVOUTꢀbitꢀinꢀSTATUS_WORD.
2)ꢀ SetsꢀtheꢀTON_MAX_FAULTꢀbitꢀinꢀSTATUS_VOUT.
3)ꢀ Respondsꢀ asꢀ specifiedꢀ inꢀ theꢀ MFR_FAULT_
RESPONSE.
4)ꢀ NotifiesꢀtheꢀhostꢀusingꢀALERTꢀassertionꢀ(ifꢀenabledꢀinꢀ
MFR_MODE).
MFR_PWM_CONFIG (E7h)
IfꢀSELECT[2:0]ꢀ=ꢀ100,ꢀtheꢀPWMn/GPOnꢀoutputꢀisꢀconfig-
ured to assert when any of the enabled channel alarms
go active. The channel alarms are enabled with the
ALARM_SELECTꢀ bitsꢀ 31:16.ꢀ Ifꢀ theꢀALARM_SELECTꢀ bitꢀ
is cleared, then the alarm from that channel is blocked. If
theꢀALARM_SELECTꢀbitꢀisꢀset,ꢀthenꢀtheꢀalarmꢀfromꢀthatꢀ
channelꢀisꢀroutedꢀtoꢀanꢀORꢀfunction,ꢀsuchꢀthatꢀanyꢀenabledꢀ
alarmꢀ assertsꢀ theꢀ GPOnꢀ output.ꢀ Theꢀ alarmꢀ functionꢀ isꢀ
chosenꢀ withꢀ theꢀ ALARM_CONFIGꢀ bitsꢀ inꢀ theꢀ MFR_
FAULT_RESPONSEꢀcommand.ꢀThisꢀfunctionꢀisꢀusefulꢀforꢀ
systemꢀdebugꢀorꢀforꢀenablingꢀsystemꢀstatusꢀLEDs.
TheꢀMFR_PWM_CONFIGꢀcommandꢀisꢀusedꢀtoꢀconfigureꢀ
theꢀindividualꢀPWMx/GPOyꢀ(xꢀ=ꢀ0–7/yꢀ=ꢀ12–19)ꢀoutputs.ꢀ
This command should not be changed while the power
suppliesꢀ areꢀ beingꢀ PWMꢀ margined.ꢀ Theꢀ MFR_PWM_
CONFIGꢀ commandꢀ isꢀ describedꢀ inꢀTable 37 and shown
in Figureꢀ13.
EachꢀPWMn/GPOnꢀpinꢀcanꢀbeꢀindependentlyꢀconfiguredꢀ
usingꢀtheꢀSELECT[2:0]ꢀbitsꢀtoꢀperformꢀoneꢀofꢀtheꢀfollowing:
●ꢀ PWMꢀmarginingꢀoperationꢀ(SELECT[2:0]ꢀ=ꢀ000)
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Table 37. MFR_PWM_CONFIG (E7h)
BIT
NAME
MEANING
TheseꢀbitsꢀareꢀonlyꢀusedꢀifꢀSELECT[2:0]ꢀ=ꢀ011ꢀorꢀ100;ꢀeachꢀbitꢀcorrespondsꢀtoꢀoneꢀchannelꢀ
(deviceꢀchannelꢀNꢀ+ꢀ16ꢀ=ꢀbitꢀnumber):
SELECT[2:0]
011ꢀ
BITꢀFUNCTION
Whenꢀthisꢀbitꢀisꢀcleared,ꢀtheꢀpowerꢀgoodꢀ(PG)ꢀorꢀGPIꢀfromꢀchannelꢀNꢀisꢀnotꢀ
usedꢀinꢀtheꢀlogicalꢀANDꢀtoꢀassertꢀtheꢀGPOnꢀoutput.ꢀWhenꢀthisꢀbitꢀisꢀset,ꢀtheꢀ
PGꢀorꢀGPIꢀisꢀused.
PG_GPI_SELECT
ALARM_SELECT
31:16
100ꢀ
Whenꢀthisꢀbitꢀisꢀcleared,ꢀtheꢀalarmꢀfromꢀchannelꢀNꢀisꢀblockedꢀfromꢀtheꢀ
logicalꢀORꢀtoꢀassertꢀtheꢀGPOꢀoutput.ꢀWhenꢀthisꢀbitꢀisꢀset,ꢀtheꢀalarmꢀsignalꢀ
isꢀroutedꢀtoꢀtheꢀlogicalꢀOR.
These bits determine the delay time to pin deassertion; when the pin is operating as a
PGn/GPInꢀorꢀalarmꢀpinꢀ(SELECT[2:0]ꢀ=ꢀ011ꢀorꢀ100):
OFF_DELAY[3:0]
0000ꢀ
DELAYꢀTIME OFF_DELAY[3:0] DELAYꢀTIME
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
0msꢀ
5msꢀ
1000ꢀ
1001ꢀ
1010ꢀ
1011ꢀ
1100ꢀ
1101ꢀ
1110ꢀ
1111ꢀ
200ms
400ms
0001ꢀ
0010ꢀ
0011ꢀ
0100ꢀ
0101ꢀ
0110ꢀ
0111ꢀ
15:12
OFF_DELAY
10msꢀ
20msꢀ
40msꢀ
60msꢀ
80msꢀ
100msꢀ
600ms
800ms
1000ms
1500ms
2000ms
4000ms
These bits determine the delay time to pin assertion; when the pin is operating as a
PGn/GPInꢀorꢀalarmꢀpinꢀ(SELECT[2:0]ꢀ=ꢀ011ꢀorꢀ100):
ON_DELAY[3:0]
0000ꢀ
DELAYꢀTIME ON_DELAY[3:0]
DELAYꢀTIME
200ms
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
0msꢀ
5msꢀ
1000ꢀ
1001ꢀ
1010ꢀ
1011ꢀ
1100ꢀ
1101ꢀ
1110ꢀ
1111ꢀ
0001ꢀ
0010ꢀ
0011ꢀ
0100ꢀ
0101ꢀ
0110ꢀ
0111ꢀ
400ms
600ms
800ms
1000ms
1500ms
2000ms
4000ms
11:8
ON_DELAY
10msꢀ
20msꢀ
40msꢀ
60msꢀ
80msꢀ
100msꢀ
0ꢀ=ꢀPWMn/GPOnꢀpush-pullꢀoutput
1ꢀ=ꢀPWMn/GPOnꢀopen-drainꢀoutput
7
PP_OD
0ꢀ=ꢀPWMn/GPOnꢀactiveꢀlow
1ꢀ=ꢀPWMn/GPOnꢀactiveꢀhigh
6
HI_LO
0
5:3
Theseꢀbitsꢀalwaysꢀreturnꢀaꢀ0.
Theseꢀbitsꢀdetermineꢀtheꢀfunctionꢀselectedꢀonꢀtheꢀpin:
SELECT[2:0]
000ꢀ
PWMn/GPOnꢀPINꢀSELECTEDꢀFUNCTION
PWMꢀoperation
ForceꢀGPOꢀassertion
ForceꢀGPOꢀdeassertion
PG/GPIꢀoperationꢀ(useꢀbitsꢀ31:16)
Alarmꢀoperationꢀ(useꢀbitsꢀ31:16)
FAULT1ꢀspecialꢀfunctionꢀ(onlyꢀPAGEꢀ7)
Reserved
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
001ꢀ
010ꢀ
011ꢀ
100ꢀ
101ꢀ
11xꢀ
2:0
SELECT[2:0]
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000
001
010
PWMx
(x = 0–7)
NOT AVAILABLE FOR
PWMn OR FAULT1 OR
FORCE GPO ASSERTION
OR DEASSERTION
FORCE GPO ASSERTION
FORCE GPO DEASSERTION
16
NOT AVAILABLE FOR
PWMn OR FAULT1
16
ALARM0–
ALARM15
PWMx/GPOy
(x = 0–6)
ACTIVE HIGH/LOW
ON_DELAY
OFF_DELAY
6
100
SELECT
AND
OR
16
OPEN DRAIN/PUSH-PULL
(x = 12–18)
16
PG0/GPI0–
PG15/GPI15
PWM7
GPO19
FAULT1
16
SELECT
AND
011
AND
FAULT1
OR
MFR_PWM_CONFIG
BITS 31:16
BITS 2:0
BITS 15:8
BIT 6
BIT 7
NOTE: SIGNALS LISTED IN ITALICS ARE INTERNAL SIGNALS THAT CONNECT TO OTHER DEVICE FUNCTIONS.
SHADED BLOCKS ARE PMBus COMMANDS.
Figure 13. MFR_PWM_CONFIG Functional Logic
theꢀOPERATIONꢀcommandꢀandꢀCONTROLnꢀpinsꢀusingꢀ
theꢀ ON_OFF_CONFIGꢀ command.ꢀ Seeꢀ theꢀ ON_OFF_
CONFIGꢀcommandꢀdescriptionꢀforꢀdetails.ꢀThisꢀselectionꢀ
would be used if the channel is being controlled by time-
based sequencing.
Delay Function
If a delay is configured either on or off, the input must
be continuously static through the delay time before the
outputꢀchangesꢀstateꢀ(seeꢀFigureꢀ9).
MFR_SEQ_CONFIG (E8h)
IfꢀSELECT[1:0]ꢀ=ꢀ01,ꢀthenꢀsequencingꢀforꢀtheꢀchannelꢀisꢀ
initiatedꢀwhenꢀsomeꢀcombinationꢀofꢀpower-goodsꢀ(PGs)ꢀ
andꢀ general-purposeꢀ inputsꢀ (GPIs)ꢀ areꢀ asserted.ꢀ Theꢀ
channels that should be used in this combination are
selectedꢀ usingꢀ theꢀ PG_GPI_SELECTꢀ bitsꢀ 31:16.ꢀ Ifꢀ theꢀ
PG_GPI_SELECTꢀ bitꢀ isꢀ cleared,ꢀ thenꢀ theꢀ associatedꢀ
channel is not used in the logical combination to assert
theꢀGPOnꢀoutput.ꢀIfꢀtheꢀPG_GPI_SELECTꢀbitꢀisꢀset,ꢀthenꢀ
theꢀpowerꢀgoodꢀorꢀGPIꢀfromꢀtheꢀchannelꢀisꢀusedꢀinꢀtheꢀ
logical combination to initiate the power-on sequencing.
This selection would be used if the channel is being con-
trolled by event-based sequencing.
TheꢀMFR_SEQ_CONFIGꢀcommandꢀisꢀusedꢀtoꢀconfigureꢀ
theꢀsequencingꢀchannelsꢀ(PAGESꢀ0–11).ꢀThisꢀcommandꢀ
should not be changed while the power supplies are
operating.ꢀ Theꢀ MFR_SEQ_CONFIGꢀ commandꢀ isꢀ
described in Tableꢀ38 and shown in Figureꢀ2.
Eachꢀchannelꢀcanꢀbeꢀindependentlyꢀconfiguredꢀtoꢀinitiateꢀ
power-onꢀsequencing,ꢀusingꢀtheꢀSELECT[1:0]ꢀbits,ꢀtoꢀoneꢀ
ofꢀtheꢀfollowingꢀconditions:
●ꢀ Waitꢀ forꢀ eitherꢀ SEQUENCE0ꢀ orꢀ SEQUENCE1ꢀ fromꢀ
ON_OFF_CONFIGꢀdecodeꢀ(SELECT[1:0]ꢀ=ꢀ00)
●ꢀ Waitꢀforꢀallꢀenabledꢀchannelꢀpower-goodꢀ(PG)ꢀorꢀGPIꢀ
toꢀbeꢀassertedꢀ(SELECT[1:0]ꢀ=ꢀ01)
IfꢀSELECT[1:0]ꢀ=ꢀ10,ꢀthenꢀsequencingꢀisꢀinitiatedꢀwhenꢀ
the channel matches the selected signature on the
SEQ pin. The signature to match on is selected with the
SEQ_MATCHꢀ bits.ꢀ Theꢀ SEQ signal is used to facilitate
event-based sequencing in multiple-device systems. This
selection would be used if the channel is being controlled
by event-based sequencing.
●ꢀ WaitꢀforꢀaꢀmatchꢀonꢀtheꢀSEQꢀpinꢀ(SELECT[2:0]ꢀ=ꢀ10)
Ifꢀ SELECT[1:0]ꢀ =ꢀ 00,ꢀ thenꢀ theꢀ channelꢀ waitsꢀ forꢀ eitherꢀ
theꢀ SEQUENCE0ꢀ orꢀ SEQUENCE1ꢀ signalꢀ toꢀ assertꢀ
before powering on. The sequence signal to use is
selectedꢀ withꢀ theꢀ SEQ_SELECTꢀ bit.ꢀ Theꢀ SEQUENCE0ꢀ
andꢀ SEQUENCE1ꢀ signalsꢀ areꢀ generatedꢀ byꢀ decodingꢀ
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ꢀ
ꢀ
ꢀ
ꢀ
00ꢀ
01ꢀ
10ꢀ
11ꢀ
MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Table 38. MFR_SEQ_CONFIG (E8h)
BIT
NAME
MEANING
TheseꢀbitsꢀareꢀonlyꢀusedꢀifꢀSELECT[1:0]ꢀ=ꢀ01;ꢀeachꢀbitꢀcorrespondsꢀtoꢀoneꢀchannel
(deviceꢀchannelꢀNꢀ+ꢀ16ꢀ=ꢀbitꢀnumber):
Whenꢀtheseꢀbitsꢀareꢀcleared,ꢀtheꢀpowerꢀgoodꢀ(PG)ꢀorꢀGPIꢀfromꢀchannelꢀNꢀisꢀnotꢀusedꢀinꢀtheꢀ
logicalꢀANDꢀtoꢀinitiateꢀpower-onꢀsequencing.ꢀWhenꢀtheseꢀbitsꢀareꢀset,ꢀtheꢀPGꢀorꢀGPIꢀisꢀused.
31:16
15:12
PG_GPI_SELECT
0
Theseꢀbitsꢀalwaysꢀreturnꢀaꢀ0.
These bits determine which SEQ signature the channel must match before initiating
powerꢀonꢀsequencing:
ꢀ 0000ꢀ Disabledꢀ
1000ꢀ
1001ꢀ
1010ꢀ
1011ꢀ
1100ꢀ
1101ꢀ
1110ꢀ
1111ꢀ
Signatureꢀ8
Signatureꢀ9
Signatureꢀ10
Signatureꢀ11
Signatureꢀ12
Signatureꢀ13
Signatureꢀ14
Signatureꢀ15
ꢀ 0001ꢀ Signatureꢀ1ꢀ
ꢀ 0010ꢀ Signatureꢀ2ꢀ
ꢀ 0011ꢀ Signatureꢀ3ꢀ
ꢀ 0100ꢀ Signatureꢀ4ꢀ
ꢀ 0101ꢀ Signatureꢀ5ꢀ
ꢀ 0110ꢀ Signatureꢀ6ꢀ
ꢀ 0111ꢀ Signatureꢀ7ꢀ
11:8
SEQ_MATCH
7:6
5:4
0
Theseꢀbitsꢀalwaysꢀreturnꢀaꢀ0.
Theseꢀbitsꢀdetermineꢀtheꢀsignalꢀthatꢀinitiatesꢀpower-onꢀsequencing:
ꢀ
SELECTEDꢀPOWER-ON
SEQUENCINGꢀCONTROLꢀSIGNAL
SEQUENCE0ꢀorꢀSEQUENCE1ꢀ(useꢀbitꢀ0)ꢀ
PG/GPIꢀlogicꢀcombinationꢀ(useꢀbitsꢀ31:16)ꢀ
SEQꢀMatchꢀ(useꢀbitsꢀ11:8)ꢀ
SELECT[1:0]
SEQUENCINGꢀTYPE
Timeꢀbased
SELECT[1:0]
Eventꢀbased
Eventꢀbased
Reservedꢀ
3:1
0
0
Theseꢀbitsꢀalwaysꢀreturnꢀaꢀ0.
0ꢀ=ꢀSEQUENCE0
1ꢀ=ꢀSEQUENCE1
SEQ_SELECT
marginꢀtheꢀpowerꢀsupply.ꢀWhenꢀmarginingꢀisꢀnotꢀactive,ꢀtheꢀ
PWMnꢀandꢀDACꢀoutputsꢀareꢀhighꢀimpedance.
MFR_MARGIN_CONFIG (DFh)
Theꢀ MFR_MARGIN_CONFIGꢀ commandꢀ configuresꢀ
bothꢀtheꢀdigitalꢀPWMnꢀoutputsꢀ(PWM0–PWM7)ꢀandꢀtheꢀ
externalꢀDS4424ꢀcurrentꢀDACꢀ(ifꢀpresent)ꢀtoꢀmarginꢀtheꢀ
associatedꢀ powerꢀ supplies.ꢀ Ifꢀ theꢀ PWMn/GPOnꢀ pinꢀ isꢀ
configuredꢀ withꢀ MFR_PWM_CONFIGꢀ forꢀ anyꢀ functionꢀ
besidesꢀ PWMꢀ operation,ꢀ thisꢀ selectionꢀ overridesꢀ theꢀ
marginingꢀ functionality.ꢀ Theꢀ MFR_MARGIN_CONFIGꢀ
command is described in Table 39.
TheꢀdeviceꢀmarginsꢀtheꢀpowerꢀsuppliesꢀwhenꢀOPERATIONꢀ
is set to one of the margin states. Margining of the supplies
does not begin until ALL channels that have been config-
uredꢀ asꢀ voltageꢀ monitoringꢀ (withꢀ orꢀ withoutꢀ sequencing)ꢀ
haveꢀ exceededꢀ theirꢀ programmedꢀ POWER_GOOD_ONꢀ
levels.ꢀ Whenꢀ thisꢀ happens,ꢀ theꢀ PWMꢀ orꢀ DACꢀ outputꢀ isꢀ
enabled and margining is initiated. The device then aver-
ages four samples of V
ꢀ forꢀ aꢀ totalꢀ timeꢀ ofꢀ 20ms.ꢀ Ifꢀ
OUT
Power-Supply Margining Operation
the measured V ꢀandꢀtheꢀtargetꢀ(setꢀbyꢀeitherꢀVOUT_
OUT
Forꢀ theꢀ powerꢀ suppliesꢀ connectedꢀ toꢀ PSEN0–PSEN7ꢀ
(PAGESꢀ 0–7),ꢀ power-supplyꢀ marginingꢀ isꢀ implementedꢀ
usingꢀ theꢀ PWM0–PWM7ꢀ outputs,ꢀ respectively.ꢀTheꢀ PWMꢀ
frequencyꢀ isꢀ 312.5kHz.ꢀ Forꢀ powerꢀ suppliesꢀ connectedꢀ toꢀ
PSEN8–PSEN11ꢀ (PAGESꢀ 8–11),ꢀ power-supplyꢀ margin-
ingꢀ isꢀ implementedꢀ usingꢀ theꢀ externalꢀ DS4424ꢀ DACꢀ out-
puts according Tableꢀ 40. The device close-loop controls
theꢀ PWMꢀ dutyꢀ cycleꢀ orꢀ DACꢀ outputꢀ currentꢀ settingꢀ toꢀ
MARGIN_HIGHꢀorꢀVOUT_MARGIN_LOW)ꢀdiffer,ꢀtheꢀPWMꢀ
dutyꢀcycleꢀorꢀtheꢀDACꢀsettingꢀisꢀadjustedꢀbyꢀoneꢀstep.ꢀTheꢀ
direction of the duty-cycle adjustment is determined by the
SLOPEꢀ bitꢀ inꢀ MFR_MARGIN_CONFIG.ꢀ Useꢀ aꢀ positiveꢀ
slopeꢀwhenꢀtheꢀDACꢀisꢀdirectlyꢀdrivingꢀtheꢀreferenceꢀvoltageꢀ
ofꢀaꢀpowerꢀsupply.ꢀUseꢀaꢀnegativeꢀslopeꢀwhenꢀtheꢀDACꢀisꢀ
injectedꢀintoꢀtheꢀpowerꢀsupply'sꢀfeedbackꢀpinꢀasꢀshownꢀinꢀ
Figureꢀ14.ꢀAllꢀchangesꢀtoꢀtheꢀDACꢀsettingꢀareꢀmadeꢀafterꢀ
averaging four samples of V ꢀoverꢀaꢀ20msꢀperiod.
OUT
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Table 39. MFR_MARGIN_CONFIG (DFh)
BIT
NAME
MEANING
DACꢀandꢀPWMꢀsettingꢀtoꢀresultingꢀvoltageꢀrelationship:
0ꢀ=ꢀNegativeꢀslopeꢀ
ꢀ
ꢀ
DACꢀsourceꢀcurrentꢀresultsꢀinꢀaꢀlowerꢀvoltage
IncreasingꢀPWMꢀdutyꢀcycleꢀresultsꢀinꢀaꢀlowerꢀvoltage
15
SLOPE
1ꢀ=ꢀPositiveꢀslope
ꢀ
ꢀ
DACꢀsourceꢀcurrentꢀresultsꢀinꢀaꢀhigherꢀvoltage
DecreasingꢀPWMꢀdutyꢀcycleꢀresultsꢀinꢀaꢀhigherꢀvoltage
0ꢀ=ꢀNormalꢀclosed-loopꢀmargining
1ꢀ=ꢀPWMꢀdutyꢀcycleꢀorꢀDACꢀvalueꢀsetꢀconstantlyꢀtoꢀtheꢀDC_DACꢀvalueꢀwhenꢀmarginingꢀinvoked
14
OPEN_LOOP
0
13:8
Theseꢀbitsꢀalwaysꢀreturnꢀaꢀ0.
Thisꢀ8-bitꢀvalueꢀhasꢀtwoꢀpurposes:
1) WithꢀPWMꢀmargining,ꢀitꢀisꢀusedꢀasꢀtheꢀinitialꢀPWMꢀdutyꢀcycleꢀwhenꢀtheꢀdeviceꢀbeginsꢀtoꢀmarginꢀaꢀ
power supply either up or down.
7:0
DC_DAC
2) Whenꢀbitꢀ14ꢀisꢀset,ꢀthisꢀvalueꢀisꢀusedꢀtoꢀsetꢀtheꢀPWMꢀdutyꢀcycleꢀorꢀtheꢀexternalꢀcurrentꢀDACꢀlevel.
If a communication error occurs between the MAX34451
Table 40. Power-Supply DAC Outputs
andꢀ theꢀ externalꢀ DS4424,ꢀ aꢀ faultꢀ occursꢀ whenꢀ theꢀ
MAX34451ꢀattemptsꢀtoꢀsetꢀtheꢀDACꢀtoꢀfullꢀscaleꢀandꢀtheꢀ
target margin value is not reached.
PAGE
POWER SUPPLY
PSEN8
DS4424 OUTPUT
OUT0
8
9
DC_DAC Value
PSEN9
OUT1
Theꢀ DC_DACꢀ valueꢀ forꢀ theꢀ channelsꢀ controlledꢀ byꢀ theꢀ
PWMnꢀ outputsꢀ canꢀ beꢀ determinedꢀ byꢀ theꢀ followingꢀ
formula.ꢀTheꢀDC_DACꢀvalueꢀforꢀtheꢀchannelsꢀcontrolledꢀ
byꢀtheꢀexternalꢀcurrentꢀDACꢀisꢀautomaticallyꢀconfiguredꢀ
byꢀtheꢀdeviceꢀandꢀsetꢀtoꢀ0x00h.
10
11
PSEN10
OUT2
PSEN11
OUT3
WhenꢀtheꢀOPERATIONꢀcommandꢀdeactivatesꢀmargining,ꢀ
andꢀtheꢀmarginingꢀhasꢀbeenꢀrunningꢀwithꢀtheꢀ“IgnoreꢀAllꢀ
Faults”ꢀ condition,ꢀ theꢀ deviceꢀ doesꢀ notꢀ beginꢀ monitoringꢀ
forꢀfaultsꢀforꢀ100msꢀafterꢀtheꢀ“MarginꢀOff”ꢀinputꢀisꢀreceivedꢀ
to allow time for the power supplies to return to a normal
condition.
PWMꢀDC_DACꢀvalueꢀ=ꢀ255ꢀxꢀ(V /V
)
FB DD
where V
is the power-supply feedback node voltage
FB
and V
is the supply voltage.
DD
Example:
V
ꢀ=ꢀ0.8V,ꢀV ꢀ=ꢀ3.3V
FB DD
Margining Faults
PWMꢀDC_DACꢀvalueꢀ=ꢀ255ꢀxꢀ(0.8/3.3)ꢀ~ꢀ62dꢀ=ꢀ0x3Eh
Theꢀ deviceꢀ detectsꢀ twoꢀ possibleꢀ marginingꢀ faults.ꢀ First,ꢀ
ifꢀtheꢀinitialꢀPWMꢀdutyꢀcycleꢀorꢀDACꢀstepꢀcausesꢀV
OUT
PWM/DAC Margining Component Selection
toꢀ exceedꢀ theꢀ targetꢀ valueꢀ (eitherꢀ highꢀ orꢀ low,ꢀ depend-
ing on whether the device has been instructed to margin
highꢀ orꢀ low,ꢀ respectively),ꢀ thisꢀ createsꢀ aꢀ fault.ꢀ Second,ꢀ
ifꢀ theꢀ targetꢀ valueꢀ cannotꢀ beꢀ reachedꢀ whenꢀ theꢀ PWMꢀ
dutyꢀ cycleꢀ orꢀ DACꢀ reachesꢀ zeroꢀ orꢀ fullꢀ scale,ꢀ thisꢀ alsoꢀ
creates a fault. If either margining fault occurs, the device
continues attempting to margin the power supply and
doesꢀtheꢀfollowing:
Figureꢀ14 shows how to implement margining by inject-
ingꢀPWMꢀvoltageꢀintoꢀaꢀpowerꢀsupply’sꢀfeedbackꢀpin.ꢀAꢀ
low-passꢀfilterꢀisꢀconnectedꢀtoꢀtheꢀPWMꢀpinꢀtoꢀfilterꢀoutꢀ
the pulsation.
Forꢀmarginꢀhighꢀoperation,ꢀtheꢀfollowingꢀequationꢀcalculatesꢀ
theꢀmaximumꢀallowableꢀresistor:
V
ꢁ0.3V ꢄR1
ꢂ
ꢃ
FB
1)ꢀ SetsꢀtheꢀMARGINꢀbitꢀinꢀSTATUS_WORD.
R
ꢀ
MH
MarginRangeHigh
100
R1
R2
C
E
S
C
E
S
V
ꢄ 1ꢅ
ꢁV ꢄ 1ꢅ
FB
D
2)ꢀ Setsꢀ theꢀ MARGIN_FAULTꢀ bitꢀ inꢀ STATUS_MFR_
SPECIFICꢀ(PAGESꢀ0–11).
OUT
D
T
U
T
U
3)ꢀ NotifiesꢀtheꢀhostꢀthroughꢀALERTꢀassertionꢀ(ifꢀenabledꢀ
whereꢀMarginRangeHighꢀisꢀtheꢀmaximumꢀrequiredꢀmarginꢀ
high range in percentage.
inꢀMFR_MODE).
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PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Forꢀmarginꢀlowꢀoperation,ꢀtheꢀfollowingꢀequationꢀcalculatesꢀ
theꢀmaximumꢀallowableꢀresistor:
Usingꢀtheꢀaboveꢀequations:
R
ꢀ=ꢀ98.8kΩ;ꢀR ꢀ=ꢀ736.3kΩ.ꢀChooseꢀR
ꢀ=ꢀ98.8kΩꢀ
PWM
MH
ML
SetꢀRꢀequalꢀtoꢀR
ꢀ-ꢀ4.7kΩꢀ=ꢀ94.1kΩ
V
ꢁ V ꢁ0.5 ꢄR1
ꢂ ꢃ
DD
ꢂ
ꢃ
PWM
FB
R
ꢀ
ML
MarginRangeLow
100
R1
R2
C
E
S
C
E
S
DACꢀ“R ”ꢀ=ꢀ(7.75)/(I ꢀxꢀMarginingꢀrangeꢀxꢀ120%)
FS
FB
V
ꢄ 1ꢁ
ꢁV ꢄ 1ꢅ
FB
T D
OUT
D
T
U
U
where I is the feedback node current.
FB
Example:
whereꢀMarginRangeLowꢀisꢀtheꢀmaximumꢀrequiredꢀmarginꢀ
low range in percentage and V is the supply voltage.
I
ꢀ=ꢀ500µA,ꢀmarginingꢀrangeꢀ=ꢀ±15%
FB
DD
DACꢀ“RFS”ꢀvalueꢀ=ꢀ(7.75)/(500µAꢀxꢀ15%ꢀxꢀ120%)ꢀ=ꢀ
86kΩ
To ensure that both the maximum high and low margin
rangesꢀcanꢀbeꢀachieved,ꢀchooseꢀaꢀresistor,ꢀR , that
PWM
Note:ꢀ40kΩꢀ<ꢀR ꢀ<ꢀ160kΩ
FS
isꢀlowerꢀofꢀR ꢀandꢀR .ꢀFurther,ꢀinꢀorderꢀtoꢀaccountꢀforꢀ
MH
ML
the presence of the ripple filter resistor, choose resistor
valueꢀforꢀ‘R’ꢀ(seeꢀFigureꢀ14)ꢀwhichꢀisꢀ4.7kΩꢀlessꢀthanꢀtheꢀ
Temperature Sensor Operation
The device can monitor up to five different temperature sen-
sors, four external sensors, plus its own internal tempera-
ture sensor. The external temperature sensors are all con-
calculatedꢀvalueꢀofꢀR
.
PWM
Whenꢀmarginingꢀhigh,ꢀtheꢀdeviceꢀsinksꢀcurrentꢀfromꢀtheꢀ
feedback node, and when margining low, the device
sourcesꢀcurrentꢀintoꢀtheꢀfeedbackꢀnode.ꢀEnsureꢀthatꢀ‘R’ꢀ
resistorꢀvalueꢀisꢀchosenꢀsuchꢀthatꢀtheꢀPWMꢀsources/sinksꢀ
notꢀmoreꢀthanꢀ200µAꢀmaximumꢀcurrentꢀwhenꢀoperatingꢀatꢀ
full margin range.
2
nected in parallel to the master I Cꢀportꢀ(MSDAꢀandꢀMSCLꢀ
pins).ꢀTheꢀdeviceꢀcanꢀsupportꢀupꢀtoꢀfourꢀDS75LVꢀdevices.
Eachꢀofꢀtheꢀenabledꢀtemperatureꢀsensorsꢀareꢀmeasuredꢀ
once per second. The internal temperature sensor is
averagedꢀfourꢀtimesꢀtoꢀreduceꢀtheꢀeffectꢀofꢀnoise.ꢀEachꢀ
time the device attempts to read a temperature sensor,
itꢀchecksꢀforꢀfaults.ꢀForꢀtheꢀinternalꢀtemperatureꢀsensor,ꢀ
aꢀfaultꢀisꢀdefinedꢀasꢀreadingꢀgreaterꢀthanꢀ+130°Cꢀorꢀlessꢀ
Example:
V =ꢀ1V,ꢀV ꢀ=ꢀ0.6V,ꢀV ꢀ=ꢀ3.3V,ꢀR1ꢀ=ꢀ33.2kΩ,ꢀR2ꢀ=ꢀꢀ49.9kΩ,ꢀ
OUTꢀ FB DD
MarginingꢀRangeꢀ=ꢀ±10%
2
thanꢀ -60°C.ꢀ Forꢀ theꢀ I C temperature sensors, a fault is
POWER SUPPLY
V
OUT
RIPPLE FILTER
R1
R2
I
FB
MAX34451
R
4.7kΩ
V
FB
FB/TRIM
PWMn
10nF
POWER SUPPLY
V
OUT
R1
R2
I
FB
DS4424
FB/TRIM
OUT
FS
R
FS
Figure 14. Margining Hardware Configurations
Maxim Integrated
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
surface-mountꢀ capacitor.ꢀ Surface-mountꢀ componentsꢀ
minimizeꢀleadꢀinductance,ꢀwhichꢀimprovesꢀperformance,ꢀ
and ceramic capacitors tend to have adequate high-
frequencyꢀresponseꢀforꢀdecouplingꢀapplications.ꢀDecoupleꢀ
theꢀ REG18ꢀ regulatorꢀ outputꢀ usingꢀ 1µFꢀ andꢀ 10nFꢀ
capacitorsꢀwithꢀaꢀmaximumꢀESRꢀofꢀ500mΩ.
Table 41. DS75LV Address Pin
Configuration
DS75LV ADDRESS PIN
CONFIGURATION
MAX34451 TEMP
SENSOR
PAGE
A2
—
0
A1
—
0
A0
—
0
16
17
18
19
20
MAX34451 internal
DS75LVꢀ(addressꢀ90h)
DS75LVꢀ(addressꢀ92h)
DS75LVꢀ(addressꢀ94h)
DS75LVꢀ(addressꢀ96h)
Open-Drain Pins
MSDA,ꢀ MSCL,ꢀ SCL,ꢀ SDA,ꢀ FAULTn, SEQ, and ALERT
are open-drain pins and require external pullup resistors
0
0
1
connected to V ꢀtoꢀrealizeꢀhighꢀlogicꢀlevels.
DD
0
1
0
PSEN0–PSEN11ꢀcanꢀbeꢀuser-configuredꢀasꢀeitherꢀCMOSꢀ
push-pullꢀ orꢀ open-drainꢀ outputs.ꢀ Whenꢀ configuredꢀ asꢀ
openꢀ drainꢀ (seeꢀ MFR_PSEN_CONFIG),ꢀ externalꢀ pullupꢀ
0
1
1
Table 42. MFR_TEMP_SENSOR_CONFIG
(F0h)
resistors connected to V ꢀareꢀ requiredꢀ toꢀrealizeꢀ highꢀ
DD
logic levels.
BIT
NAME
ENABLE
0
MEANING
Keep-Alive Circuit
0ꢀ=ꢀTemperatureꢀsensorꢀdisabled
1ꢀ=ꢀTemperatureꢀsensorꢀenabled
In systems where the power to the device may not always
beꢀpresent,ꢀaꢀkeep-aliveꢀcircuitꢀconsistingꢀofꢀaꢀSchottkyꢀ
diode and a bulk capacitor can be added to allow the
device time to orderly shut down the power supplies it
isꢀ controllingꢀ andꢀ writeꢀ faultꢀ logꢀ (ifꢀ configured)ꢀ toꢀ flashꢀ
memory before power is lost.
15
14:0
Theseꢀbitsꢀalwaysꢀreturnꢀaꢀ0.
defined as a communication access failure. Temperature-
sensor faults are reported by setting the temperature
readingꢀ toꢀ 7FFFh.ꢀAꢀ temperature-sensorꢀ faultꢀ resultsꢀ in
theꢀsettingꢀofꢀtheꢀTEMPERATUREꢀbitꢀinꢀSTATUS_WORDꢀ
and ALERTꢀisꢀassertedꢀ(ifꢀenabledꢀinꢀMFR_MODE).ꢀNoꢀ
bitsꢀareꢀsetꢀinꢀSTATUS_TEMPERATURE.ꢀOnꢀresetꢀofꢀtheꢀ
device,ꢀifꢀtheꢀdeviceꢀcannotꢀinitializeꢀtheꢀexternalꢀDS75LVꢀ
device,ꢀtheꢀTEMPERATUREꢀbitꢀinꢀSTATUS_WORDꢀisꢀsetꢀ
and ALERTꢀisꢀassertedꢀ(ifꢀenabledꢀinꢀMFR_MODE),ꢀbutꢀ
theꢀ deviceꢀ doesꢀ notꢀ attemptꢀ toꢀ reinitializeꢀ theꢀ DS75LVꢀ
untilꢀ8000hꢀisꢀwrittenꢀtoꢀMFR_TEMP_SENSOR_CONFIG.ꢀ
Readingꢀ disabledꢀ temperatureꢀ sensorsꢀ returnsꢀ aꢀ fixedꢀ
valueꢀofꢀ0000h.
Configuration Port
Someꢀ applicationsꢀ requireꢀ theꢀ abilityꢀ toꢀ configureꢀ theꢀ
deviceꢀwhenꢀtheꢀdeviceꢀhasꢀbeenꢀmountedꢀonꢀaꢀPCB.ꢀInꢀ
such applications, a 3- or 4-wire header can be added to
2
allow access to the slave I C pins.
Resistor-Dividers and Source Impedance for
RSn Inputs
Theꢀ maximumꢀ full-scaleꢀ voltageꢀ onꢀ theꢀ ADCꢀ inputsꢀ isꢀ
2.048Vꢀ (nominal).ꢀ Aꢀ resistor-dividerꢀ mustꢀ beꢀ usedꢀ toꢀ
measureꢀ voltagesꢀ greaterꢀ thanꢀ 1.8V.ꢀ Theꢀ maximumꢀ
sourceꢀimpedanceꢀtoꢀtheꢀRSnꢀinputsꢀisꢀdeterminedꢀbyꢀtheꢀ
ADC_TIMEꢀbitsꢀinꢀMFR_MODE.ꢀSeeꢀtheꢀRecommended
Operating Conditions section for more details.
Upꢀ toꢀ fourꢀ DS75LVꢀ digitalꢀ temperatureꢀ sensorsꢀ canꢀ beꢀ
controlledꢀ byꢀ theꢀ MAX34451.ꢀ Theꢀ A0–A2ꢀ pinsꢀ onꢀ theꢀ
DS75LVꢀshouldꢀbeꢀconfiguredꢀasꢀshownꢀinꢀTable 41. The
thermostatꢀfunctionꢀonꢀtheꢀDS75LVꢀisꢀnotꢀusedꢀandꢀhenceꢀ
theꢀO.S.ꢀoutputꢀshouldꢀbeꢀleftꢀopenꢀcircuit.
Protecting Input Pins
InꢀapplicationsꢀwhereꢀvoltagesꢀcanꢀbeꢀappliedꢀtoꢀtheꢀRSnꢀ
MFR_TEMP_SENSOR_CONFIG (F0h)
orꢀCONTROLnꢀsignals,ꢀwhenꢀV
or V
is grounded,
DD
DDA
TheꢀMFR_TEMP_SENSOR_CONFIGꢀcommandꢀisꢀusedꢀ
toꢀconfigureꢀtheꢀtemperatureꢀsensors.ꢀTheꢀMFR_TEMP_
SENSOR_CONFIGꢀcommandꢀisꢀdescribedꢀinꢀTable 42.
aꢀ seriesꢀ 100Ωꢀ resistorꢀ isꢀ recommendedꢀ toꢀ protectꢀ theꢀ
device by limiting power dissipation.
Exposed Pad Grounding
TheꢀdeviceꢀusesꢀtheꢀexposedꢀpadꢀofꢀtheꢀTQFNꢀpackageꢀ
Applications Information
asꢀtheꢀcommonꢀgroundꢀ(V )ꢀforꢀtheꢀentireꢀdevice.ꢀTheꢀ
exposed pad must be connected to the local ground plane.
V
, V
, and REG18 Decoupling
SS
DD DDA
To achieve the best results when using the device,
decouple V and V power inputs each with a
DD
DDA
0.1µFꢀcapacitor.ꢀIfꢀpossible,ꢀuseꢀaꢀhigh-quality,ꢀceramic,ꢀ
Maxim Integrated
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Typical Operating Circuit
OPTIONAL
MARGINING
SUPPORT FOR
CHANNELS
8–11
OPTIONAL
CURRENT
MONITORING
DS4424
I C 4-CHANNEL
CURRENT DAC
(I C ADDRESS A0h)
2
2
LOAD
IN
POWER
SUPPLY
OUT
CURRENT-
SENSE
AMPLIFIER
TRIM
OPTIONAL
REMOTE
TEMP
SENSORS
(UP TO 4)
EN
DS75LV
I C TEMP
SENSOR
(I C ADDRESSES
90/92/94/96h)
MSDA
MSCL
2
2
V
DDA
PSEN0–
PSEN11
3.3V
OPTIONAL
V
DD
MAX34451
PWM0–
PWM7
OPTIONAL
KEEP
ALIVE
OPTIONAL
CONFIGURATION
ACCESS
SDA
SCL
HOST
INTERFACE
ALERT
ADDR
RS0–
RS15
ONLY REQUIRED
IF THE MONITORED
VOLTAGE IS > 1.8V
RST
POWER
CONTROL
FAULT0
CONTROL0
CONTROL1
REG18
RSG0
RSG1
V
SS
(EP)
Ordering Information
PART NUMBER
MAX34451ETNA2+
MAX34451ETNA2+T
MAX34451ETNA3+
MAX34451ETNA3+T
MAX34451ETNA4+**
MAX34451ETNA4+T**
PIN-PACKAGE
56ꢀTQFN-EP*
56ꢀTQFN-EP*
56ꢀTQFN-EP*
56ꢀTQFN-EP*
56ꢀTQFN-EP*
56ꢀTQFN-EP*
FIRMWARE
0005
STATUS
ACTIVE
ACTIVE
ACTIVE
ACTIVE
0005
0007
0007
0009
ACTIVE
ACTIVE
0009
+Denotes a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
*EP = Exposed pad.
**MAX34451ETNA4+ and MAX34451ETNA4+T are recommended for all future designs.
Note: Part operates over the -40°C to +85°C temperature range.
Maxim Integrated
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MAX34451
PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
Revision History
REVISION REVISION
PAGES
CHANGED
DESCRIPTION
NUMBER
DATE
0
3/13
Initial release
Added V rise time and V
—
source impedance to Recommended Operating
DD
DD
1
2
8/13
5/15
2, 17
1, 66
Conditions table, updated the 7-bit slave addresses in Table 4
UpdatedꢀBenefits and Features section and moved Ordering Information to page 1
(Firmwareꢀupdate)ꢀUpdatedꢀOrdering Information, Table 3, Table 5, Table 7, SEQ Pin
Operation section, Clear Faults (03h) section, POWER_GOOD_ONꢀsection,ꢀFigureꢀ7,ꢀ
Table 25, MFR_VOUT_MIN (D7h) section, MFR_FAULT_RETRY (DAh) section, Table
36, Power-Supply Margining Operation section, DC-DAC Valueꢀsection,ꢀPWM/DACꢀ
Margining Component Selectionꢀsection,ꢀFigureꢀ14,ꢀKeep-Alive Circuit section
1, 15-16,
21-22, 26,
ꢀ32,ꢀ37-38,ꢀ
41, 46, 53,
57, 63-65
3
4
4/16
3/17
AddedꢀfutureꢀpartsꢀtoꢀMAX34451ETNA2+ꢀandꢀMAX34451ETNA2+TꢀinꢀtheꢀOrdering
Information section.
75
UpdatedꢀTableꢀ3ꢀandꢀTOFF_DELAY (64h), MFR_PSEN_CONFIG (D2h), MFR_NV_
FAULT_LOG (DCh), and MFR_PWM_CONFIG (E7h)ꢀsections.ꢀRemovedꢀfutureꢀ
partꢀdesignationsꢀforꢀMAX34451ETNA2+ꢀandꢀMAX34451ETNA2+T,ꢀandꢀremovedꢀ
MAX34451ETNA1+ꢀandꢀMAX34451ENTA1+T
22, 45, 52,
61,ꢀ68,ꢀ75
5
6
7
7/17
5/18
6/18
AddedꢀMAX34451ETNA3+ꢀandꢀMAX34451ETNA3+TꢀtoꢀtheꢀOrdering Information table.
75
UpdatedꢀTableꢀ3,ꢀTableꢀ4,ꢀSMBus/PMBus Operation Examples, and PMBus
Operation, POWER_GOOD_ON (5Eh), POWER_GOOD_OFF (5Fh), MFR_NV_
FAULT_LOG (DCh) and Power-Supply Margining Operationꢀsections;ꢀUpdatedꢀtheꢀ
Ordering Information table.
22, 24, 27
45, 61, 71, 75
8
9/19
UpdatedꢀOrdering Information
UpdatedꢀOrdering Information
75
75
9
10/19
For pricing, delivery, and ordering information, please visit Maxim Integrated’s online storefront at https://www.maximintegrated.com/en/storefront/storefront.html.
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses
are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits)
shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
©
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
ꢀ 2019ꢀMaximꢀIntegratedꢀProducts,ꢀInc.ꢀꢀ
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