MAX17504ATP+ [MAXIM]
Switching Regulator, Current-mode, 5.85A, 2450kHz Switching Freq-Max, BICMOS, TQFN-20;
| 型号： | MAX17504ATP+ |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Switching Regulator, Current-mode, 5.85A, 2450kHz Switching Freq-Max, BICMOS, TQFN-20 信息通信管理 开关 |
| 文件： | 总26页 (文件大小：1549K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
EVALUATION KIT AVAILABLE
MAX17504
4.5V–60V, 3.5A, High-Efficiency, Synchronous
Step-Down DC-DC Converter
with Internal Compensation
General Description
Benefits and Features
The MAX17504/MAX17504S high-efficiency, high-
voltage, synchronously rectified step-down converter with
dual integrated MOSFETs operates over a 4.5V to 60V
●
EliminatesꢀExternalꢀComponentsꢀandꢀReducesꢀTotalꢀCost
• NoꢀSchottky-SynchronousꢀOperationꢀforꢀHighꢀ
EfficiencyꢀandꢀReducedꢀCost
input. It delivers up to 3.5A and 0.9V to 90% V output
• Internal compensation for Stable Operation at Any
Output Voltage
• All Ceramic Capacitor Solution: Ultra-Compact
Layout with as Few as Eight External Components
ReduceꢀNumberꢀofꢀDC-DCꢀRegulatorsꢀtoꢀStock
• Wideꢀ4.5Vꢀtoꢀ60VꢀInputꢀVoltageꢀRange
IN
voltage. Built-in compensation across the output voltage
range eliminates the need for external components. The
feedback (FB) regulation accuracy over -40°C to +125°C
is ±1.1%. The device is available in a compact (5mm x
5mm) TQFN lead (Pb)-free package with an exposed pad.
Simulation models are available.
●
• 0.9V to 90% V Output Voltage
IN
• Delivers Up to 3.5A Over Temperature
• 100kHzꢀtoꢀ2.2MHzꢀAdjustableꢀFrequencyꢀwithꢀ
External Synchronization
• MAX17504SꢀAllowsꢀHigherꢀFrequencyꢀOfꢀOperation
• Available in a 20-Pin, 5mm x 5mm TQFN Package
ReduceꢀPowerꢀDissipation
• PeakꢀEfficiencyꢀ>ꢀ90%
• PFMꢀandꢀDCMꢀModesꢀforꢀHighꢀLight-LoadꢀEfficiency
• Shutdown Current = 2.8FA (typ)
The device features
a peak-current-mode control
architecture with a MODE feature that can be used to
operate the device in pulse-width modulation (PWM),
pulse-frequency modulation (PFM), or discontinuous
mode (DCM) control schemes. PWM operation provides
constant frequency operation at all loads, and is useful
in applications sensitive to switching frequency. PFM
operation disables negative inductor current and
additionally skips pulses at light loads for high efficiency.
DCM features constant frequency operation down to
lighter loads than PFM mode, by not skipping pulses,
but only disabling negative inductor current at light loads.
DCM operation offers efficiency performance that lies
between PWM and PFM modes. The MAX17504S offers
a lower minimum on-time that allows for higher switching
frequencies and a smaller solution size.
●
●
OperateꢀReliablyꢀ
• Hiccup-ModeꢀCurrentꢀLimitꢀandꢀAutoretryꢀStartup
• Built-In Output Voltage Monitoring—(Open-Drain
RESET Pin)
• ResistorꢀProgrammableꢀEN/UVLOꢀThreshold
• AdjustableꢀSoft-StartꢀandꢀPre-BiasedꢀPower-Up
• HighꢀIndustrialꢀ-40°Cꢀtoꢀ+125°CꢀAmbientꢀOperatingꢀ
TemperatureꢀRange/-40°Cꢀtoꢀ+150°CꢀJunctionꢀ
TemperatureꢀRange
A programmable soft-start feature allows users to reduce
input inrush current. The device also incorporates an
output enable/undervoltage lockout pin (EN/UVLO) that
allows the user to turn on the part at the desired input-
voltage level. An open-drain RESET pin provides a
delayed power-good signal to the system upon achieving
successful regulation of the output voltage.
Ordering Information appears at end of data sheet.
Applications
●ꢀ IndustrialꢀPowerꢀSupplies
●ꢀ DistributedꢀSupplyꢀRegulation
●ꢀ BaseꢀStationꢀPowerꢀSupplies
●ꢀ WallꢀTransformerꢀRegulation
●ꢀ High-VoltageꢀSingle-BoardꢀSystems
●ꢀ General-PurposeꢀPoint-of-Load
19-6844; Rev 3; 5/17
MAX17504
4.5V–60V, 3.5A, High-Efficiency, Synchronous
Step-Down DC-DC Converter
with Internal Compensation
Absolute Maximum Ratings (Note 1)
V
ꢀtoꢀPGND .........................................................-0.3V to +65V
SGNDꢀtoꢀPGND....................................................-0.3V to +0.3V
LXꢀTotalꢀRMSꢀCurrent ........................................................±5.6A
Output Short-Circuit Duration....................................Continuous
IN
EN/UVLOꢀtoꢀSGND ...............................................-0.3V to +65V
LXꢀtoꢀPGND................................................-0.3V to (V + 0.3V)
IN
BSTꢀtoꢀPGND........................................................-0.3V to +70V
Continuous Power Dissipation (T = +70°C) (multilayer board)
A
BST to LX.............................................................-0.3V to +6.5V
TQFN (derate 33.3mW/°C above T = +70°C)......2666.7mW
A
BST to V
FB, CF, RESET, SS, MODE, SYNC,
RTꢀtoꢀSGND .....................................................-0.3V to +6.5V
...........................................................-0.3V to +65V
JunctionꢀTemperature......................................................+150°C
StorageꢀTemperatureꢀRange............................ -65NC to +160°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow).......................................+260°C
CC
V
ꢀtoꢀSGND.......................................................-0.3V to +6.5V
CC
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.
Package Information
PACKAGE TYPE: 20 TQFN
Package Code
T2055+4
21-0140
90-0009
Outline Number
Land Pattern Number
THERMAL RESISTANCE, FOUR-LAYER BOARD
JunctionꢀtoꢀAmbientꢀ(θ
)
30°C/W
2°C/W
JA
JunctionꢀtoꢀCaseꢀ(θ
)
JC
For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”,
“#”,ꢀorꢀ“-”ꢀinꢀtheꢀpackageꢀcodeꢀindicatesꢀRoHSꢀstatusꢀonly.ꢀPackageꢀdrawingsꢀmayꢀshowꢀaꢀdifferentꢀsuffixꢀcharacter,ꢀbutꢀtheꢀdrawingꢀ
pertainsꢀtoꢀtheꢀpackageꢀregardlessꢀofꢀRoHSꢀstatus.
PackageꢀthermalꢀresistancesꢀwereꢀobtainedꢀusingꢀtheꢀmethodꢀdescribedꢀinꢀJEDECꢀspecificationꢀJESD51-7,ꢀusingꢀaꢀfour-layerꢀboard.ꢀ
For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial.
Note 1: ꢀJunctionꢀtemperatureꢀgreaterꢀthanꢀ+125°Cꢀdegradesꢀoperatingꢀlifetimes.
Electrical Characteristics
(V = V
ꢀ=ꢀ24V,ꢀR
= 40.2kIꢀ(500kHz),ꢀC
= 2.2µF, V
= V
= V
= V
= 0V, LX = SS = RESET =
IN
EN/UVLO
RT
VCC
PGND
SGND
MODE
SYNC
open, V
to V = 5V, V = 1V, T = -40°C to +125°C, unless otherwise noted. Typical values are at T = +25°C. All voltages are
BST
LX FB A A
referencedꢀtoꢀSGND,ꢀunlessꢀotherwiseꢀnoted.)ꢀ(Noteꢀ2)
PARAMETER
INPUT SUPPLY (V
SYMBOL
CONDITIONS
MIN
TYP MAX UNITS
)
IN
InputꢀVoltageꢀRange
V
4.5
60
V
IN
Input Shutdown Current
I
V
V
V
= 0V (shutdown mode)
2.8
118
162
1.16
4.5
IN-SH
EN/UVLO
= 1V, MODE = RT=ꢀopen
µA
FB
FB
I
Q_PFM
= 1V, MODE = open
Input Quiescent Current
I
DCM mode, V = 0.1V
LX
1.8
Q_DCM
mA
Normal switching mode, f
=ꢀ500kHz,
SW
I
9.5
Q_PWM
V
= 0.8V
FB
www.maximintegrated.com
Maxim Integrated │ 2
MAX17504
4.5V–60V, 3.5A, High-Efficiency, Synchronous
Step-Down DC-DC Converter
with Internal Compensation
Electrical Characteristics (continued)
(V = V
ꢀ=ꢀ24V,ꢀR
= 40.2kIꢀ(500kHz),ꢀC
= 2.2µF, V
= V
= V
= V
= 0V, LX = SS = RESET =
IN
EN/UVLO
RT
VCC
PGND
SGND
MODE
SYNC
open, V
to V = 5V, V = 1V, T = -40°C to +125°C, unless otherwise noted. Typical values are at T = +25°C. All voltages are
BST
LX FB A A
referencedꢀtoꢀSGND,ꢀunlessꢀotherwiseꢀnoted.)ꢀ(Noteꢀ2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP MAX UNITS
ENABLE/UVLO (EN/UVLO)
V
V
V
V
rising
1.19 1.215 1.24
1.068 1.09 1.111
ENR
EN/UVLO
EN/UVLO
EN/UVLO
EN/UVLO Threshold
V
V
falling
= 0V, T = +25ºC
ENF
EN/UVLO Input Leakage Current
I
-50
0
+50
nA
EN
A
LDO
6V < V < 60V, I
= 1mA
IN
VCC
V
ꢀOutputꢀVoltageꢀRange
V
4.75
5
5.25
100
V
CC
CC
1mAꢀ≤ꢀI
ꢀ≤ꢀ25mA
VCC
V
V
Current Limit
Dropout
I
V
V
V
V
= 4.3V, V = 6V
26.5
4.2
54
mA
V
CC
VCC-MAX
CC
IN
V
= 4.5V, I
= 20mA
CC
CC-DO
IN
VCC
V
rising
falling
4.05
3.65
4.2
3.8
4.3
3.9
CC_UVR
CC
CC
V
UVLO
V
CC
V
CC_UVF
POWER MOSFET AND BST DRIVER
High-SideꢀnMOSꢀOn-Resistance
Low-SideꢀnMOSꢀOn-Resistance
R
I
I
= 0.3A
= 0.3A
165
80
325
150
mΩ
mΩ
DS-ONH
LX
LX
R
DS-ONL
V
= V - 1V, V = V
+ 1V,
LX
IN
LX
PGND
LX Leakage Current
I
-2
+2
µA
LX_LKG
T = +25ºC
A
SOFT-START (SS)
Charging Current
FEEDBACK (FB)
I
V
= 0.5V
4.7
5
5.3
µA
SS
SS
MODEꢀ=ꢀSGNDꢀorꢀMODEꢀ=ꢀV
0.89
0.9
0.91
CC
FBꢀRegulationꢀVoltage
V
V
FB_REG
MODE = open
0.89 0.915 0.936
FB Input Bias Current
I
0 < V < 1V, T = +25ºC
-50
+50
nA
FB
FB
A
MODE
V
CC
1.6
-
V
MODE = V
(DCM mode)
M-DCM
CC
MODE Threshold
V
V
MODE = open (PFM mode)
V
/2
M-PFM
CC
V
MODEꢀ=ꢀGNDꢀ(PWMꢀmode)
1.4
M-PWM
CURRENT LIMIT
Peak Current-Limit Threshold
I
4.4
4.9
5.1
5.7
0
5.85
6.7
A
A
PEAK-LIMIT
I
RUNAWAY-LIMIT
RunawayꢀCurrent-LimitꢀThreshold
MODE = open or MODE = V
-0.16
+0.16
CC
Valley Current-Limit Threshold
I
A
A
SINK-LIMIT
MODEꢀ=ꢀGND
-1.8
PFM Current-Limit Threshold
I
MODE = open
0.6
0.75
0.9
PFM
www.maximintegrated.com
Maxim Integrated │ 3
MAX17504
4.5V–60V, 3.5A, High-Efficiency, Synchronous
Step-Down DC-DC Converter
with Internal Compensation
Electrical Characteristics (continued)
(V = V
ꢀ=ꢀ24V,ꢀR
= 40.2kIꢀ(500kHz),ꢀC
= 2.2µF, V
= V
= V
= V
= 0V, LX = SS = RESET =
IN
EN/UVLO
RT
VCC
PGND
SGND
MODE
SYNC
open, V
to V = 5V, V = 1V, T = -40°C to +125°C, unless otherwise noted. Typical values are at T = +25°C. All voltages are
BST
LX FB A A
referencedꢀtoꢀSGND,ꢀunlessꢀotherwiseꢀnoted.)ꢀ(Noteꢀ2)
PARAMETER
RT AND SYNC
SYMBOL
CONDITIONS
MIN
TYP MAX UNITS
R
R
R
R
R
ꢀ=ꢀ210kΩ
ꢀ=ꢀ102kΩ
ꢀ=ꢀ40.2kΩ
ꢀ=ꢀ8.06kΩ
= OPEN
90
100
200
500
110
220
525
RT
RT
RT
RT
RT
180
475
Switching Frequency
f
kHz
SW
1950 2200 2450
460
500
540
1.1 x
1.4 x
f
SW
SYNCꢀFrequencyꢀCaptureꢀRange
SYNC Pulse Width
f
ꢀsetꢀbtꢀR
kHz
ns
V
SW
RT
f
SW
50
V
2.1
IH
SYNC Threshold
V
0.8
0.6
IL
V
Undervoltage Trip Level to
FB
V
0.56
0.58
V
FB-HICF
CauseꢀHiccup
HICCUPꢀTimeout
(Note 3)
32768
Cycles
ns
MAX17504
135
80
Minimum On-Time
t
ON-MIN
MAX17504S
55
5
ns
Minimum Off-Time
LX Dead Time
t
140
160
ns
OFF-MIN
ns
RESET
RESET Output Level Low
I
= 1mA
0.4
V
RESET
RESET Output Leakage Current
T
= T = +25ºC, V = 5.5V
RESET
-0.1
+0.1
µA
A
J
V
Threshold for RESET
OUT
V
V
V
falling
rising
90.5
92
95
94
%
%
FB-OKF
FB
FB
Assertion
V
Threshold for RESET
OUT
V
93.8
97.2
FB-OKR
Deassertion
RESET Deassertion Delay After FB
Reachesꢀ95%ꢀRegulation
1024
Cycles
THERMAL SHUTDOWN
Thermal Shutdown Threshold
ThermalꢀShutdownꢀHysteresis
Temperature rising
165
10
ºC
ºC
Note 2: All limits are 100% tested at +25°C. Limits over temperature are guaranteed by design.
Note 3: See the Overcurrent Protection/HICCUP Mode section for more details.
www.maximintegrated.com
Maxim Integrated │ 4
MAX17504
4.5V–60V, 3.5A, High-Efficiency, Synchronous
Step-Down DC-DC Converter
with Internal Compensation
Typical Operating Characteristics
(V = V
= 24V, V
= V
= 0V, C
= 2 x 2.2µF, C
= 2.2µF, C
= 0.1µF, C ꢀ=ꢀ12,000pF,ꢀRTꢀ=ꢀMODEꢀ=ꢀopen,ꢀT = T
IN
EN/UVLO
PGND
SGND
VIN
VCC
BST SS A J
= -40°C to +125°C, unless otherwise noted. Typical values are at T = +25°C.ꢀAllꢀvoltagesꢀareꢀreferencedꢀtoꢀSGND,ꢀunlessꢀotherwiseꢀnoted.)
A
MAX17504 3.3V OUTPUT
EFFICIENCY vs. LOAD CURRENT
(PWM MODE, FIGURE 4 CIRCUIT)
MAX17504 5V OUTPUT
EFFICIENCY vs. LOAD CURRENT
(PWM MODE, FIGURE 3 CIRCUIT)
MAX17504S 5V OUTPUT
EFFICIENCY vs. LOAD CURRENT
(PWM MODE, FIGURE 5 CIRCUIT)
toc01
toc02
toc01a
100
90
80
70
60
50
40
100
90
80
70
60
50
40
100
90
80
70
60
50
40
30
VIN = 48V
VIN = 36V
VIN = 24V
VIN = 12V
VIN = 36V
VIN = 24V
VIN = 48V
VIN = 36V
VIN = 24V
VIN = 12V
VIN = 48V
VIN = 12V
MODE = SGND
MODE = SGND
MODE = SGND
2.5 3.0 3.5
0
500 1000 1500 2000 2500 3000 3500
LOAD CURRENT (mA)
0
500 1000 1500 2000 2500 3000 3500
LOAD CURRENT (mA)
0.0
0.5
1.0
1.5
2.0
LOAD CURRENT (A)
MAX17504 5V OUTPUT
EFFICIENCY vs. LOAD CURRENT
(PFM MODE, FIGURE 3 CIRCUIT)
MAX17504S 3.3V OUTPUT
EFFICIENCY vs. LOAD CURRENT
(PWM MODE, FIGURE 6 CIRCUIT)
100
toc03
toc02a
100
90
80
70
60
50
40
30
90
80
70
VIN = 48V
VIN = 36V
VIN = 48V
60
50
40
30
20
VIN = 24V VIN = 36V
VIN = 12V
VIN = 24V
VIN = 12V
MODE = OPEN
MODE = SGND
2.5 3.0 3.5
3500
1
10
100
1000
0.0
0.5
1.0
1.5
2.0
LOAD CURRENT (mA)
LOAD CURRENT (A)
MAX17504 3.3V OUTPUT
EFFICIENCY vs. LOAD CURRENT
(PFM MODE, FIGURE 4 CIRCUIT)
MAX17504S 5V OUTPUT
EFFICIENCY vs. LOAD CURRENT
(PFM MODE, FIGURE 5 CIRCUIT)
toc04
toc03a
100
90
80
70
60
50
40
30
100
90
80
70
60
50
40
30
VIN = 48V
VIN = 36V
VIN = 48V
VIN = 36V
VIN = 24V
VIN = 12V
VIN = 24V
VIN = 12V
MODE = OPEN
MODE = OPEN
1.0
1
10
100
1000
3500
3.5
0.0
0.1
LOAD CURRENT (A)
LOAD CURRENT (mA)
www.maximintegrated.com
Maxim Integrated │ 5
MAX17504
4.5V–60V, 3.5A, High-Efficiency, Synchronous
Step-Down DC-DC Converter
with Internal Compensation
Typical Operating Characteristics (continued)
(V = V
= 24V, V
= V
= 0V, C
= 2 x 2.2µF, C
= 2.2µF, C
= 0.1µF, C ꢀ=ꢀ12,000pF,ꢀRTꢀ=ꢀMODEꢀ=ꢀopen,ꢀT = T
IN
EN/UVLO
PGND
SGND
VIN
VCC
BST SS A J
= -40°C to +125°C, unless otherwise noted. Typical values are at T = +25°C.ꢀAllꢀvoltagesꢀareꢀreferencedꢀtoꢀSGND,ꢀunlessꢀotherwiseꢀnoted.)
A
MAX17504S 5V OUTPUT
EFFICIENCY vs. LOAD CURRENT
(DCM MODE, FIGURE 5 CIRCUIT)
MAX17504 5V OUTPUT
EFFICIENCY vs. LOAD CURRENT
(DCM MODE, FIGURE 3 CIRCUIT)
MAX17504S 3.3V OUTPUT
EFFICIENCY vs. LOAD CURRENT
(PFM MODE, FIGURE 6 CIRCUIT)
toc05
toc05a
toc04a
100
90
80
70
60
50
40
30
100
90
80
70
60
50
40
30
20
10
0
100
90
80
70
60
50
40
30
VIN = 48V
VIN = 36V
VIN = 48V
VIN = 36V
VIN = 24V
VIN = 12V
V
IN = 24V
VIN = 48V
IN = 36V
VIN = 12V
V
VIN = 24V
VIN = 12V
MODE = VCC
1000
MODE = VCC
1.0
3.5
MODE = OPEN
1.0
1
10
100
3500
0.0
0.1
3.5
0.0
0.1
LOAD CURRENT (A)
LOAD CURRENT (mA)
LOAD CURRENT (A)
MAX17504S 3.3V OUTPUT
EFFICIENCY vs. LOAD CURRENT
(DCM MODE, FIGURE 6 CIRCUIT)
MAX17504 3.3V OUTPUT
EFFICIENCY vs. LOAD CURRENT
(DCM MODE, FIGURE 4 CIRCUIT)
toc06
toc06a
100
90
80
70
60
50
40
30
100
VIN = 48V
VIN = 36V
VIN = 48V
90
80
70
60
50
40
30
20
10
VIN = 36V
VIN = 24V
VIN = 24V
VIN = 12V
VIN = 12V
MODE = VCC
MODE = VCC
1.0
3500
1
10
100
1000
0.0
0.1
LOAD CURRENT (mA)
LOAD CURRENT (A)
MAX17504S 5V OUTPUT
LOAD AND LINE REGULATION
(PWM MODE, FIGURE 5 CIRCUIT)
MAX17504 5V OUTPUT
LOAD AND LINE REGULATION
(PWM MODE, FIGURE 3 CIRCUIT)
toc07
toc07a
5.08
5.07
5.06
5.05
5.04
5.03
5.02
5.01
5.00
4.99
4.98
5.00
4.99
4.98
4.97
4.96
4.95
4.94
4.93
4.92
4.91
VIN = 48V
VIN = 36V
VIN = 36V
VIN = 24V
VIN = 12V
VIN = 24V
VIN = 12V
VIN = 48V
MODE = SGND
MODE = SGND
2.5 3.0 3.5
0
500 1000 1500 2000 2500 3000 3500
LOAD CURRENT (mA)
0.0
0.5
1.0
1.5
2.0
LOAD CURRENT (A)
www.maximintegrated.com
Maxim Integrated │ 6
MAX17504
4.5V–60V, 3.5A, High-Efficiency, Synchronous
Step-Down DC-DC Converter
with Internal Compensation
Typical Operating Characteristics (continued)
(V = V
= 24V, V
= V
= 0V, C
= 2 x 2.2µF, C
= 2.2µF, C
= 0.1µF, C ꢀ=ꢀ12,000pF,ꢀRTꢀ=ꢀMODEꢀ=ꢀopen,ꢀT = T
IN
EN/UVLO
PGND
SGND
VIN
VCC
BST SS A J
= -40°C to +125°C, unless otherwise noted. Typical values are at T = +25°C.ꢀAllꢀvoltagesꢀareꢀreferencedꢀtoꢀSGND,ꢀunlessꢀotherwiseꢀnoted.)
A
MAX17504S 3.3V OUTPUT
LOAD AND LINE REGULATION
(PWM MODE, FIGURE 6 CIRCUIT)
MAX17504 3.3V OUTPUT
LOAD AND LINE REGULATION
(PWM MODE, FIGURE 4 CIRCUIT)
MAX17504 5V OUTPUT
LOAD AND LINE REGULATION
(PFM MODE, FIGURE 3 CIRCUIT)
toc08
toc09
toc08a
3.36
3.35
3.34
3.33
3.32
3.31
3.30
3.29
3.28
3.27
3.26
5.5
5.4
5.3
5.2
5.1
5.0
4.9
4.8
4.7
4.6
4.5
3.40
3.39
3.38
3.37
3.36
3.35
3.34
3.33
3.32
VIN = 24V
VIN = 48V
VIN = 48V
VIN = 24V
VIN = 36V
VIN = 12V
VIN = 48V
VIN = 12V
VIN = 36V
VIN = 24V
VIN = 12V
VIN = 36V
MODE = SGND
MODE = OPEN
MODE = SGND
2.5 3.0 3.5
0
500 1000 1500 2000 2500 3000 3500
LOAD CURRENT (mA)
0
500 1000 1500 2000 2500 3000 3500
LOAD CURRENT (mA)
0.0
0.5
1.0
1.5
2.0
LOAD CURRENT (A)
MAX17504 3.3V OUTPUT
LOAD AND LINE REGULATION
(PFM MODE, FIGURE 4 CIRCUIT)
MAX17504S 5V OUTPUT
LOAD AND LINE REGULATION
(PFM MODE, FIGURE 5 CIRCUIT)
5.25
toc10
toc09a
3.6
5.20
3.5
3.4
3.3
3.2
3.1
3.0
VIN = 12V
VIN = 48V
5.15
5.10
5.05
5.00
4.95
4.90
4.85
4.80
4.75
VIN = 12V
VIN = 24V
VIN = 48V
VIN = 36V
VIN = 24V
VIN=36V
MODE = OPEN
MODE = OPEN
2.5 3.0 3.5
0
500 1000 1500 2000 2500 3000 3500
LOAD CURRENT (mA)
0.0
0.5
1.0
1.5
2.0
LOAD CURRENT (A)
MAX17504S 3.3V OUTPUT
LOAD AND LINE REGULATION
(PFM MODE, FIGURE 6 CIRCUIT)
SWITCHING FREQUENCY
vs. RT RESISTANCE
toc11
toc10a
2400
2200
2000
1800
1600
1400
1200
1000
800
3.60
3.55
3.50
3.45
3.40
3.35
3.30
3.25
3.20
VIN = 48V
VIN = 36V
VIN = 24V
600
VIN = 12V
400
200
MODE = OPEN
2.5 3.0 3.5
0
0
20
40
60
80
100
0.0
0.5
1.0
1.5
2.0
RRT (kΩ)
LOAD CURRENT (A)
www.maximintegrated.com
Maxim Integrated │ 7
MAX17504
4.5V–60V, 3.5A, High-Efficiency, Synchronous
Step-Down DC-DC Converter
with Internal Compensation
Typical Operating Characteristics (continued)
(V = V
= 24V, V
= V
= 0V, C
= 2 x 2.2µF, C
= 2.2µF, C
= 0.1µF, C ꢀ=ꢀ12,000pF,ꢀRTꢀ=ꢀMODEꢀ=ꢀopen,ꢀT = T
IN
EN/UVLO
PGND
SGND
VIN
VCC
BST SS A J
= -40°C to +125°C, unless otherwise noted. Typical values are at T = +25°C.ꢀAllꢀvoltagesꢀareꢀreferencedꢀtoꢀSGND,ꢀunlessꢀotherwiseꢀnoted.)
A
MAX17504S 5V OUTPUT
MAX17504 5V OUTPUT
SOFT-START/SHUTDOWN FROM EN/UVLO
SOFT-START/SHUTDOWN FROM EN/UVLO
(3.5A LOAD CURRENT, FIGURE 5 CIRCUIT)
(3.5A LOAD CURRENT, FIGURE 3 CIRCUIT)
toc12a
toc12
VEN/UVLO
5V/div
2V/div
VEN/UVLO
2V/div
VOUT
VOUT
2V/div
IOUT
2A/div
5V/div
IOUT
VRESET
2A/div
5V/div
MODE = SGND
2ms/div
MODE = SGND
VRESET
1ms/div
MAX17504S 3.3V OUTPUT
SOFT-START/SHUTDOWN FROM EN/UVLO
(3.5A LOAD CURRENT, FIGURE 6 CIRCUIT)
MAX17504 3.3V OUTPUT
SOFT-START/SHUTDOWN FROM EN/UVLO,
(3.5A LOAD CURRENT, FIGURE 4 CIRCUIT)
toc13a
toc13
VEN/UVLO
VEN/UVLO
5V/div
2V/div
VOUT
2V/div
VOUT
2V/div
IOUT
1A/div
5V/div
IOUT
2A/div
5V/div
VRESET
VRESET
MODE = SGND
MODE = SGND
2mS/div
1ms/div
MAX17504S 5V OUTPUT
SOFT-START/SHUTDOWN FROM EN/UVLO
(PFM MODE, 5mA LOAD CURRENT, FIGURE 5 CIRCUIT)
MAX17504 5V OUTPUT
SOFT-START/SHUTDOWN FROM EN/UVLO
(PFM MODE, 5mA LOAD CURRENT, FIGURE 3 CIRCUIT)
toc14a
toc14
MODE = OPEN
VEN/UVLO
5V/div
VEN/UVLO
2V/div
1V/div
5V/div
VOUT
VOUT
1V/div
5V/div
VRESET
MODE = OPEN
2mS/div
2ms/div
www.maximintegrated.com
Maxim Integrated │ 8
MAX17504
4.5V–60V, 3.5A, High-Efficiency, Synchronous
Step-Down DC-DC Converter
with Internal Compensation
Typical Operating Characteristics (continued)
(V = V
= 24V, V
= V
= 0V, C
= 2 x 2.2µF, C
= 2.2µF, C
= 0.1µF, C ꢀ=ꢀ12,000pF,ꢀRTꢀ=ꢀMODEꢀ=ꢀopen,ꢀT = T
IN
EN/UVLO
PGND
SGND
VIN
VCC
BST SS A J
= -40°C to +125°C, unless otherwise noted. Typical values are at T = +25°C.ꢀAllꢀvoltagesꢀareꢀreferencedꢀtoꢀSGND,ꢀunlessꢀotherwiseꢀnoted.)
A
MAX17504 5V OUTPUT
SOFT-START WITH 2.5V PREBIAS
(PWM MODE, FIGURE 3 CIRCUIT)
MAX17504S 3.3V OUTPUT
SOFT-START/SHUTDOWN FROM EN/UVLO
(PFM MODE, 5mA LOAD CURRENT, FIGURE 6 CIRCUIT)
MAX17504 3.3V OUTPUT
SOFT-START/SHUTDOWN FROM EN/UVLO
(PFM MODE, 5mA LOAD CURRENT, FIGURE 4 CIRCUIT)
toc16
toc15a
toc15
VEN/UVLO
2V/div
VEN/UVLO
VEN/UVLO
2V/div
5V/div
2V/div
5V/div
VOUT
1V/div
5V/div
1V/div
5V/div
VOUT
VOUT
VRESET
VRESET
MODE = SGND
1ms/div
MODE = OPEN
MODE = OPEN
2ms/div
2ms/div
MAX17504S 5V OUTPUT
SOFT-START WITH 2.5V PREBIAS
(PWM MODE, FIGURE 5 CIRCUIT)
MAX17504 3.3V OUTPUT
SOFT-START WITH 2.5V PREBIAS
(PFM MODE, FIGURE 4 CIRCUIT)
toc16a
toc17
5V/div
1V/div
VEN/UVLO
VEN/UVLO
2V/div
1V/div
VOUT
VRESET
5V/div
VOUT
MODE = OPEN
MODE = SGND
1ms/div
VRESET
5V/div
1mS/div
MAX17504 5V OUTPUT
STEADY-STATE SWITCHING WAVEFORMS
(3.5A LOAD CURRENT, FIGURE 3 CIRCUIT)
MAX17504S 3.3V OUTPUT
SOFT-START WITH 2.5V PREBIAS
(PWM MODE, FIGURE 6 CIRCUIT)
toc18
toc17a
VOUT
(AC)
20mV/div
VEN/UVLO
5V/div
1V/div
10V/div
2A/div
VLX
ILX
VOUT
5V/div
1μs/div
MODE = SGND
1mS/div
VRESET
www.maximintegrated.com
Maxim Integrated │ 9
MAX17504
4.5V–60V, 3.5A, High-Efficiency, Synchronous
Step-Down DC-DC Converter
with Internal Compensation
Typical Operating Characteristics (continued)
(V = V
= 24V, V
= V
= 0V, C
= 2 x 2.2µF, C
= 2.2µF, C
= 0.1µF, C ꢀ=ꢀ12,000pF,ꢀRTꢀ=ꢀMODEꢀ=ꢀopen,ꢀT = T
IN
EN/UVLO
PGND
SGND
VIN
VCC
BST SS A J
= -40°C to +125°C, unless otherwise noted. Typical values are at T = +25°C.ꢀAllꢀvoltagesꢀareꢀreferencedꢀtoꢀSGND,ꢀunlessꢀotherwiseꢀnoted.)
A
MAX17504S 5V OUTPUT
STEADY-STATE SWITCHING WAVEFORMS
(3.5A LOAD CURRENT, FIGURE 5 CIRCUIT)
MAX17504S 5V OUTPUT
STEADY-STATE SWITCHING WAVEFORMS
(NO LOAD CURRENT, FIGURE 5 CIRCUIT)
MAX17504 5V OUTPUT
STEADY-STATE SWITCHING WAVEFORMS
(PWM MODE, NO LOAD, FIGURE 3 CIRCUIT)
toc19a
toc18a
toc19
MODE = SGND
MODE = SGND
VOUT
(AC)
20mV/div
VOUT
(AC)
VOUT
(AC)
50mV/
20mV/di
10V/div
VLX
VLX
10V/div
2A/div
10V/div
1A/div
VLX
ILX
500mA/d
ILX
1μs/div
MODE = SGND
ILX
1µs/div
1µS/div
MAX17504 5V OUTPUT
STEADY-STATE SWITCHING WAVEFORMS
(PFM MODE, 25mA LOAD, FIGURE 3 CIRCUIT)
MAX17504S 5V OUTPUT
STEADY-STATE SWITCHING WAVEFORMS
(PFM MODE, 25mA LOAD CURRENT, FIGURE 5 CIRCUIT)
toc20
toc20a
MODE = OPEN
VOUT
(AC)
100mV/div
VOUT
(AC)
100mV/div
10V/div
VLX
10V/div
VLX
ILX
500mA/div
MODE = OPEN
500mA/div
ILX
10μs/div
4μs/div
MAX17504 5V OUTPUT
STEADY-STATE SWITCHING WAVEFORMS
(DCM MODE, 25mA LOAD, FIGURE 3 CIRCUIT)
MAX17504S 5V OUTPUT
STEADY-STATE SWITCHING WAVEFORMS
(DCM MODE, 150mA LOAD CURRENT, FIGURE 5 CIRCUIT)
toc21
toc21a
MODE = VCC
MODE = VCC
VOUT
(AC)
20mV/div
VOUT
(AC)
20mV/div
10V/div
VLX
VLX
10V/div
ILX
200mA/div
ILX
500mA/div
1μs/div
1μs/div
www.maximintegrated.com
Maxim Integrated │ 10
MAX17504
4.5V–60V, 3.5A, High-Efficiency, Synchronous
Step-Down DC-DC Converter
with Internal Compensation
Typical Operating Characteristics (continued)
(V = V
= 24V, V
= V
= 0V, C
= 2 x 2.2µF, C
= 2.2µF, C
= 0.1µF, C ꢀ=ꢀ12,000pF,ꢀRTꢀ=ꢀMODEꢀ=ꢀopen,ꢀT = T
IN
EN/UVLO
PGND
SGND
VIN
VCC
BST SS A J
= -40°C to +125°C, unless otherwise noted. Typical values are at T = +25°C.ꢀAllꢀvoltagesꢀareꢀreferencedꢀtoꢀSGND,ꢀunlessꢀotherwiseꢀnoted.)
A
MAX17504 5V OUTPUT
LOAD CURRENT STEPPED FROM 1.7`5A TO 3.5A
MAX17504S 5V OUTPUT
LOAD CURRENT STEPPED FROM 1.75A TO 3.5A
(PWM MODE, FIGURE 3 CIRCUIT)
(PWM MODE, FIGURE 5 CIRCUIT)
toc22
toc22a
VOUT
(AC)
100mV/div
VOUT
AC
100mV/div
IOUT
2A/div
MODE = SGND
ILX
2A/div
40μs/div
MODE = SGND
100μS/div
MAX17504 3.3V OUTPUT
LOAD CURRENT STEPPED FROM 1.75A TO 3.5A
MAX17504S 3.3V OUTPUT
LOAD CURRENT STEPPED FROM 1.75A TO 3.5A
(PWM MODE, FIGURE 4 CIRCUIT)
toc23
(PWM MODE, FIGURE 6 CIRCUIT)
toc23a
VOUT
(AC)
100mV/div
VOUT
AC
100mV/div
2A/div
IOUT
MODE = SGND
ILX
2A/div
100μs/div
MODE = SGND
100μS/div
MAX17504S 5V OUTPUT
LOAD CURRENT STEPPED FROM NO LOAD TO 1.75A
MAX17504 5V OUTPUT
LOAD CURRENT STEPPED FROM NO LOAD TO 1.75A
(PWM MODE, FIGURE 3 CIRCUIT)
(PWM MODE, FIGURE 5 CIRCUIT)
toc24
toc24a
VOUT
(AC)
100mV/div
VOUT
AC
100mV/div
IOUT
1A/div
MODE = SGND
ILX
1A/div
MODE = SGND
40μs/div
100μS/div
www.maximintegrated.com
Maxim Integrated │ 11
MAX17504
4.5V–60V, 3.5A, High-Efficiency, Synchronous
Step-Down DC-DC Converter
with Internal Compensation
Typical Operating Characteristics (continued)
(V = V
= 24V, V
= V
= 0V, C
= 2 x 2.2µF, C
= 2.2µF, C
= 0.1µF, C ꢀ=ꢀ12,000pF,ꢀRTꢀ=ꢀMODEꢀ=ꢀopen,ꢀT = T
IN
EN/UVLO
PGND
SGND
VIN
VCC
BST SS A J
= -40°C to +125°C, unless otherwise noted. Typical values are at T = +25°C.ꢀAllꢀvoltagesꢀareꢀreferencedꢀtoꢀSGND,ꢀunlessꢀotherwiseꢀnoted.)
A
MAX17504S 3.3V OUTPUT
LOAD CURRENT STEPPED FROM NO LOAD TO 1.75A
MAX17504 3.3V OUTPUT
LOAD CURRENT STEPPED FROM NO LOAD TO 1.75A
(PWM MODE, FIGURE 6 CIRCUIT)
(PWM MODE, FIGURE 4 CIRCUIT)
toc25a
toc25
VOUT
(AC)
100mV/div
VOUT
AC
100mV/div
1A/div
IOUT
MODE = SGND
ILX
1A/div
MODE = SGND
100μs/div
100μS/div
MAX17504 5V OUTPUT
LOAD CURRENT STEPPED FROM 5mA TO 1.75A
MAX17504S 5V OUTPUT
LOAD CURRENT STEPPED FROM 5MA TO 1.75A
(PFM MODE, FIGURE 3 CIRCUIT)
(PFM MODE, FIGURE 5 CIRCUIT)
toc26
toc26a
VOUT
(AC)
100mV/div
VOUT
AC
100mV/div
1A/div
IOUT
MODE = OPEN
1A/div
ILX
2ms/div
MODE = OPEN
1mS/div
MAX17504 3.3V OUTPUT
LOAD CURRENT STEPPED FROM 5mA TO 1.75A
MAX17504S 3.3V OUTPUT
LOAD CURRENT STEPPED FROM 5MA TO 1.75A
(PFM MODE, FIGURE 4 CIRCUIT)
(PFM MODE, FIGURE 6 CIRCUIT)
toc27
toc27a
VOUT
(AC)
100mV/div
VOUT
AC
100mV/div
IOUT
1A/div
MODE = OPEN
ILX
1A/div
MODE = OPEN
2ms/div
2mS/div
www.maximintegrated.com
Maxim Integrated │ 12
MAX17504
4.5V–60V, 3.5A, High-Efficiency, Synchronous
Step-Down DC-DC Converter
with Internal Compensation
Typical Operating Characteristics (continued)
(V = V
= 24V, V
= V
= 0V, C
= 2 x 2.2µF, C
= 2.2µF, C
= 0.1µF, C ꢀ=ꢀ12,000pF,ꢀRTꢀ=ꢀMODEꢀ=ꢀopen,ꢀT = T
IN
EN/UVLO
PGND
SGND
VIN
VCC
BST SS A J
= -40°C to +125°C, unless otherwise noted. Typical values are at T = +25°C.ꢀAllꢀvoltagesꢀareꢀreferencedꢀtoꢀSGND,ꢀunlessꢀotherwiseꢀnoted.)
A
MAX17504 5V OUTPUT
LOAD CURRENT STEPPED FROM 50mA TO 1.75A
MAX17504S 5V OUTPUT
LOAD CURRENT STEPPED FROM 50mA TO 1.75A
(DCM MODE, FIGURE 3 CIRCUIT)
(DCM MODE, FIGURE 5 CIRCUIT)
toc28
toc28a
VOUT
(AC)
100mV/div
VOUT (AC)
100mV/div
1A/div
IOUT
MODE = VCC
IOUT
1A/div
200μs/div
MODE = VCC
200μs/div
MAX17504 3.3V OUTPUT
LOAD CURRENT STEPPED FROM 50mA TO 1.75A
MAX17504S 3.3V OUTPUT
LOAD CURRENT STEPPED FROM 50mA TO 1.75A
(DCM MODE, FIGURE 4 CIRCUIT)
(DCM MODE, FIGURE 6 CIRCUIT)
toc29
toc29a
VOUT
(AC)
100mV/div
VOUT (AC)
100mV/div
IOUT
1A/div
MODE = VCC
IOUT
1A/div
200μs/div
MODE = VCC
200μs/div
MAX17504S 5V OUTPUT
OVERLOAD PROTECTION
(FIGURE 5 CIRCUIT)
MAX17504 5V OUTPUT
OVERLOAD PROTECTION
(FIGURE 3 CIRCUIT)
toc30a
toc30
VOUT
2V/div
50mV/div
VOUT
1A/div
IOUT
IOUT
1A/div
20ms/div
10ms/div
www.maximintegrated.com
Maxim Integrated │ 13
MAX17504
4.5V–60V, 3.5A, High-Efficiency, Synchronous
Step-Down DC-DC Converter
with Internal Compensation
Typical Operating Characteristics (continued)
(V = V
= 24V, V
= V
= 0V, C
= 2 x 2.2µF, C
= 2.2µF, C
= 0.1µF, C ꢀ=ꢀ12,000pF,ꢀRTꢀ=ꢀMODEꢀ=ꢀopen,ꢀT = T
IN
EN/UVLO
PGND
SGND
VIN
VCC
BST SS A J
= -40°C to +125°C, unless otherwise noted. Typical values are at T = +25°C.ꢀAllꢀvoltagesꢀareꢀreferencedꢀtoꢀSGND,ꢀunlessꢀotherwiseꢀnoted.)
A
MAX17504S 5V OUTPUT
APPLICATION OF EXTERNAL CLOCK AT 1.2MHz,
MAX17504 5V OUTPUT
APPLICATION OF EXTERNAL CLOCK AT 700kHz
(FIGURE 5 CIRCUIT)
toc31a
(FIGURE 3 CIRCUIT)
toc31
VLX
10V/div
VLX
10V/div
2V/div
VSYNC
2V/div
MODE = SGND
MODE = SGND
2μs/div
2μs/div
MAX17504S 5V OUTPUT
4 BODE PLOT
(3.5A LOAD CURRENT, FIGURE 5 CIRCUIT)
MAX17504 5V OUTPUT
BODE PLOT
(3.5A LOAD CURRENT, FIGURE 3 CIRCUIT)
toc32a
40
30
toc32140
60
50
100
50
120
100
80
PHASE
40
30
20
10
PHASE
20
10
0
60
GAIN
GAIN
40
20
0
0
0
-10
-20
-10
-20
-20
-40
CROSSOVER FREQUENCY = 48.4kHz
PHASE MARGIN = 62.3°
CROSSOVER FREQUENCY = 86kHz
PHASE MARGIN = 58.9°
-50
-30
-40
-30
103
-60
105
104
FREQUENCY (Hz)
100K
10K
1K
FREQUENCY (Hz)
MAX17504S 3.3V OUTPUT
BODE PLOT
(3.5A LOAD CURRENT, FIGURE 6 CIRCUIT)
MAX17504 3.3V OUTPUT
BODE PLOT
(3.5A LOAD CURRENT, FIGURE 4 CIRCUIT)
toc33a
40
20
60
toc33 140
100
120
100
80
50
40
30
PHASE
PHASE
50
20
10
0
60
GAIN
0
-20
-40
GAIN
40
20
0
0
-10
-20
-20
-40
CROSSOVER FREQUENCY = 82.3kHz
PHASE MARGIN = 59.4°
CROSSOVER FREQUENCY = 52.7KHz
PHASE MARGIN = 62.4°
-50
-30
-40
-60
104
103
105
100K
10K
1K
FREQUENCY (Hz)
FREQUENCY (Hz)
www.maximintegrated.com
Maxim Integrated │ 14
MAX17504
4.5V–60V, 3.5A, High-Efficiency, Synchronous
Step-Down DC-DC Converter
with Internal Compensation
Pin Configuration
TOP VIEW
15
14
13
12
11
RT
FB
10
9
PGND 16
LX 17
LX 18
LX 19
MAX17504/
MAX17504S
8
CF
7
SS
+
20
6
SYNC
BST
1
2
3
4
5
TQFN
5mm × 5mm
ꢀ EXPOSED PAD (CONNECT TO SIGNAL GROUND).
Pin Description
PIN
NAME
FUNCTION
Power-Supply Input. 4.5V to 60V input supply range. Connect the V ꢀpinsꢀtogether.ꢀDecoupleꢀtoꢀPGNDꢀ
IN
1, 2, 3
V
with two 2.2µF capacitors; place the capacitors close to the V ꢀandꢀPGNDꢀpins.ꢀReferꢀtoꢀtheꢀMAX17504/
IN
IN
MAX17504S EV kit data sheet for a layout example.
Enable/Undervoltage Lockout. Drive EN/UVLO high to enable the output voltage. Connect to the
4
5
EN/UVLO center of the resistor-divider between V ꢀandꢀSGNDꢀtoꢀsetꢀtheꢀinputꢀvoltageꢀatꢀwhichꢀtheꢀMAX17504/
IN
MAX17504S turns on. Pull up to V for always on operation.
IN
Open-Drain RESET Output. The RESET output is driven low if FB drops below 92% of its set value.
RESET goes high 1024 clock cycles after FB rises above 95% of its set value.
RESET
The device can be synchronized to an external clock using this pin. See the External Frequency
Synchronization section for more details.
6
7
SYNC
SS
Soft-StartꢀInput.ꢀConnectꢀaꢀcapacitorꢀfromꢀSSꢀtoꢀSGNDꢀtoꢀsetꢀtheꢀsoft-startꢀtime.
Atꢀswitchingꢀfrequenciesꢀlowerꢀthanꢀ500kHz,ꢀconnectꢀaꢀcapacitorꢀfromꢀCFꢀtoꢀFB.ꢀLeaveꢀCFꢀopenꢀifꢀtheꢀ
switchingꢀfrequencyꢀisꢀequalꢀtoꢀorꢀmoreꢀthanꢀ500kHz.ꢀSeeꢀtheꢀLoop Compensation section for more
details.
8
CF
FeedbackꢀInput.ꢀConnectꢀFBꢀtoꢀtheꢀcenterꢀtapꢀofꢀanꢀexternalꢀresistor-dividerꢀfromꢀtheꢀoutputꢀtoꢀSGNDꢀtoꢀ
set the output voltage. See the Adjusting Output Voltage section for more details.
9
FB
ConnectꢀaꢀresistorꢀfromꢀRTꢀtoꢀSGNDꢀtoꢀsetꢀtheꢀregulator’sꢀswitchingꢀfrequency.ꢀLeaveꢀRTꢀopenꢀforꢀtheꢀ
defaultꢀ500kHzꢀfrequency.ꢀSeeꢀtheꢀSetting the Switching Frequency (RT) section for more details.
10
RT
MODEꢀconfiguresꢀtheꢀMAX17504/MAX17504SꢀtoꢀoperateꢀinꢀPWM,ꢀPFMꢀorꢀDCMꢀmodesꢀofꢀoperation.ꢀ
LeaveꢀMODEꢀunconnectedꢀforꢀPFMꢀoperationꢀ(pulseꢀskippingꢀatꢀlightꢀloads).ꢀConnectꢀMODEꢀtoꢀSGNDꢀ
11
MODE
for constant-frequency PWM operation at all loads. Connect MODE to V
for DCM operation. See the
CC
MODE Setting section for more details.
www.maximintegrated.com
Maxim Integrated │ 15
MAX17504
4.5V–60V, 3.5A, High-Efficiency, Synchronous
Step-Down DC-DC Converter
with Internal Compensation
Pin Description (continued)
PIN
12
NAME
FUNCTION
V
5V LDO Output. Bypass V ꢀwithꢀaꢀ2.2µFꢀceramicꢀcapacitanceꢀtoꢀSGND.
CC
CC
13
SGND
AnalogꢀGround
PowerꢀGround.ꢀConnectꢀtheꢀPGNDꢀpinsꢀexternallyꢀtoꢀtheꢀpowerꢀgroundꢀplane.ꢀConnectꢀtheꢀSGNDꢀandꢀ
14, 15, 16
PGND
PGNDꢀpinsꢀtogetherꢀatꢀtheꢀgroundꢀreturnꢀpathꢀofꢀtheꢀV ꢀbypassꢀcapacitor.ꢀReferꢀtoꢀtheꢀMAX17504/
CC
MAX17504S EV kit data sheet for a layout example.
17, 18, 19
20
LX
Switching Node. Connect LX pins to the switching side of the inductor.
Boost Flying Capacitor. Connect a 0.1µF ceramic capacitor between BST and LX.
BST
Exposedꢀpad.ꢀConnectꢀtoꢀtheꢀSGNDꢀpin.ꢀConnectꢀtoꢀaꢀlargeꢀcopperꢀplaneꢀbelowꢀtheꢀICꢀtoꢀimproveꢀheatꢀ
dissipationꢀcapability.ꢀAddꢀthermalꢀviasꢀbelowꢀtheꢀexposedꢀpad.ꢀReferꢀtoꢀtheꢀMAX17504/MAX17504SꢀEVꢀ
kit data sheet for a layout example.
—
EP
Block Diagram
BST
MAX17504/MAX17504S
V
5V
CC
LDO
V
IN
SGND
CURRENTꢀSENSE
LOGIC
LX
PWM/
PFM/
EN/UVLO
HICCUP
LOGIC
HICCUP
1.215V
RT
PGND
OSCILLATOR
SYNC
CF
FB
MODE
SELECTION
LOGIC
ERROR AMPLIFIER/
LOOP COMPENSATION
MODE
V
CC
V
= 0.9V
SWITCHOVER
LOGIC
BG
SLOPE
COMPENSATION
RESET
5µA
SS
FB
RESET
LOGIC
EN/UVLO
HICCUP
www.maximintegrated.com
Maxim Integrated │ 16
MAX17504
4.5V–60V, 3.5A, High-Efficiency, Synchronous
Step-Down DC-DC Converter
with Internal Compensation
PFM Mode Operation
Detailed Description
PFM mode of operation disables negative inductor current
and additionally skips pulses at light loads for high
efficiency. In PFM mode, the inductor current is forced to
a fixed peak of 750mA every clock cycle until the output
rises to 102.3% of the nominal voltage. Once the output
reaches 102.3% of the nominal voltage, both the high-side
and low-side FETs are turned off and the device enters
hibernate operation until the load discharges the output to
101.1% of the nominal voltage. Most of the internal blocks
are turned off in hibernate operation to save quiescent
current. After the output falls below 101.1% of the nominal
voltage, the device comes out of hibernate operation,
turns on all internal blocks, and again commences the
process of delivering pulses of energy to the output until it
reaches 102.3% of the nominal output voltage.
The MAX17504/MAX17504S high-efficiency, high-voltage,
synchronously rectified step-down converter with dual
integrated MOSFETs operates over a 4.5V to 60V input.
It delivers up to 3.5A and 0.9V to 90% V output voltage.
IN
Built-in compensation across the output voltage range
eliminates the need for external components. The feedback
(FB) regulation accuracy over -40°C to +125°C is ±1.1%.
The device features a peak-current-mode control
architecture. An internal transconductance error
amplifier produces an integrated error voltage at an
internal node that sets the duty cycle using a PWM
comparator, a high-side current-sense amplifier, and a
slope-compensation generator. At each rising edge of
the clock, the high-side MOSFET turns on and remains
on until either the appropriate or maximum duty cycle
is reached, or the peak current limit is detected. During
theꢀhigh-sideꢀMOSFET’sꢀon-time,ꢀtheꢀinductorꢀcurrentꢀ
ramps up. During the second half of the switching
cycle, the high-side MOSFET turns off and the low-side
MOSFET turns on. The inductor releases the stored
energy as its current ramps down and provides current
to the output.
The advantage of the PFM mode is higher efficiency at
light loads because of lower quiescent current drawn from
supply. The disadvantage is that the output-voltage ripple
is higher compared to PWM or DCM modes of operation
and switching frequency is not constant at light loads.
DCM Mode Operation
DCM mode of operation features constant frequency
operation down to lighter loads than PFM mode, by not
skipping pulses but only disabling negative inductor
current at light loads. DCM operation offers efficiency
performance that lies between PWM and PFM modes.
The device features a MODE pin that can be used to operate
the device in PWM, PFM, or DCM control schemes. The
deviceꢀ integratesꢀ adjustable-inputꢀ undervoltageꢀ lockout,ꢀ
adjustableꢀsoft-start,ꢀopenꢀRESET, and external frequency
synchronization features. The MAX17504S offers a
lower minimum on-time that allows for higher switching
frequencies and a smaller solution size.
Linear Regulator (VCC
)
An internal linear regulator (V ) provides a 5V nominal
CC
Mode Selection (MODE)
supply to power the internal blocks and the low-side
The logic state of the MODE pin is latched when V
CC
MOSFET driver. The output of the linear regulator (V
)
CC
and EN/UVLO voltages exceed the respective UVLO
rising thresholds and all internal voltages are ready to
allow LX switching. If the MODE pin is open at power-up,
the device operates in PFM mode at light loads. If the
MODE pin is grounded at power-up, the device operates
in constant-frequency PWM mode at all loads. Finally,
should be bypassed with a 2.2µF ceramic capacitor
toꢀ SGND.ꢀ Theꢀ MAX17504/MAX17504Sꢀ employsꢀ anꢀ
undervoltage lockout circuit that disables the internal
linear regulator when V
falls below 3.8V (typ).
CC
Setting the Switching Frequency (RT)
if the MODE pin is connected to V
at power-up, the
The switching frequency of the MAX17504/MAX17504S
canꢀ beꢀ programmedꢀ fromꢀ 100kHzꢀ toꢀ 2.2MHzꢀ byꢀ usingꢀ
aꢀ resistorꢀ connectedꢀ fromꢀ RTꢀ toꢀ SGND.ꢀ Theꢀ switchingꢀ
CC
device operates in constant-frequency DCM mode at light
loads. State changes on the MODE pin are ignored during
normal operation.
frequency (f ) is related to the resistor connected at the
SW
RTꢀpinꢀ(R ) by the following equation:
RT
PWM Mode Operation
3
In PWM mode, the inductor current is allowed to go negative.
PWM operation provides constant frequency operation at
all loads, and is useful in applications sensitive to switching
frequency.ꢀHowever,ꢀtheꢀPWMꢀmodeꢀofꢀoperationꢀgivesꢀlowerꢀ
efficiency at light loads compared to PFM and DCM modes
of operation.
21×10
R
≅
− 1.7
RT
f
SW
whereꢀR ꢀisꢀinꢀkΩꢀandꢀf ꢀisꢀinꢀkHz.ꢀLeavingꢀtheꢀRTꢀpinꢀ
RT
SW
open causes the device to operate at the default switching
frequencyꢀofꢀ500kHz.ꢀSeeꢀTable 1ꢀforꢀRTꢀresistorꢀvaluesꢀ
for a few common switching frequencies.
www.maximintegrated.com
Maxim Integrated │ 17
MAX17504
4.5V–60V, 3.5A, High-Efficiency, Synchronous
Step-Down DC-DC Converter
with Internal Compensation
device under high input voltage, short-circuit conditions
Table 1. Switching Frequency vs. RT Resistor
when there is insufficient output voltage available to
restore the inductor current that was built up during the
ON period of the step-down converter. One occurrence
of the runaway current limit triggers a hiccup mode. In
addition, if due to a fault condition, feedback voltage
drops to 0.58V (typ) anytime after soft-start is complete,
hiccup mode is triggered. In hiccup mode, the converter
is protected by suspending switching for a hiccup timeout
period of 32,768 clock cycles. Once the hiccup timeout
period expires, soft-start is attempted again. Note that
when soft-start is attempted under an overload condition,
if feedback voltage does not exceed 0.58V, the device
switches at half the programmed switching frequency.
Hiccupꢀmodeꢀofꢀoperationꢀensuresꢀlowꢀpowerꢀdissipationꢀ
under output short-circuit conditions.
SWITCHING FREQUENCY (kHz)
RT RESISTOR (kΩ)
500
100
OPEN
210
200
102
400
49.9
19.1
8.06
1000
2200
Operating Input Voltage Range
The minimum and maximum operating input voltages for
a given output voltage should be calculated as follows:
V
+ (I
× (R
+ 0.15))
OUT
OUT(MAX)
DCR
)
OFF(MAX)
V
=
IN(MIN)
1- (f
× t
SW(MAX)
RESET Output
+ (I
× 0.175)
OUT(MAX)
The MAX17504/MAX17504S includes
a
RESET
comparator to monitor the output voltage. The open-
drain RESET output requires an external pullup resistor.
RESET goes high (high-impedance) 1024 switching
cycles after the regulator output increases above 95%
of the designed nominal regulated voltage. RESET goes
low when the regulator output voltage drops to below 92%
of the nominal regulated voltage. RESET also goes low
during thermal shutdown.
V
OUT
× t
ON(MIN)
V
=
IN(MAX)
f
SW(MAX)
where V
is the steady-state output voltage, I
OUT(MAX)
OUT
isꢀtheꢀmaximumꢀloadꢀcurrent,ꢀR
is the DC resistance
DCR
of the inductor, f
is the maximum switching
is the worst-case minimum switch
SW(MAX)
frequency, t
OFF(MAX)
Prebiased Output
off-time (160ns), and t
is the worst-case minimum
ON(MIN)
When the MAX17504/MAX17504S starts into a prebiased
output, both the high-side and the low-side switches are
turned off so that the converter does not sink current from
theꢀoutput.ꢀHigh-sideꢀandꢀlow-sideꢀswitchesꢀdoꢀnotꢀstartꢀ
switching until the PWM comparator commands the first
PWM pulse, at which point switching commences. The
output voltage is then smoothly ramped up to the target
value in alignment with the internal reference.
switch on-time (135ns for the MAX17504, 80ns for the
MAX17504S).
External Frequency Synchronization (SYNC)
The internal oscillator of the MAX17504/MAX17504S can
be synchronized to an external clock signal on the SYNC
pin. The external synchronization clock frequency must
be between 1.1 x f
and 1.4 x f , where f
is the
SW
SW
SW
frequencyꢀprogrammedꢀbyꢀtheꢀRTꢀresistor.ꢀTheꢀminimumꢀ
external clock pulse-width high should be greater than
50ns.ꢀ Seeꢀ theꢀ RTꢀ andꢀ SYNCꢀ sectionꢀ inꢀ theꢀ Electrical
Characteristics table for details.
Thermal-Shutdown Protection
Thermal-shutdown protection limits total power dissipation
inꢀ theꢀ MAX17504/MAX17504S.ꢀ Whenꢀ theꢀ junctionꢀ
temperature of the device exceeds +165°C, an on-chip
thermal sensor shuts down the device, allowing the device
to cool. The thermal sensor turns the device on again
afterꢀ theꢀ junctionꢀ temperatureꢀ coolsꢀ byꢀ 10°C. Soft-start
resets during thermal shutdown. Carefully evaluate the
total power dissipation (see the Power Dissipation section)
to avoid unwanted triggering of the thermal shutdown in
normal operation.
Overcurrent Protection/HICCUP Mode
The MAX17504/MAX17504S is provided with a robust
overcurrent protection scheme that protects the device
under overload and output short-circuit conditions. A
cycle-by-cycle peak current limit turns off the high-side
MOSFET whenever the high-side switch current exceeds
an internal limit of 5.1A (typ). A runaway current limit on
the high-side switch current at 5.7A (typ) protects the
www.maximintegrated.com
Maxim Integrated │ 18
MAX17504
4.5V–60V, 3.5A, High-Efficiency, Synchronous
Step-Down DC-DC Converter
with Internal Compensation
Select a low-loss inductor closest to the calculated
value with acceptable dimensions and having the lowest
possible DC resistance. The saturation current rating
Applications Information
Input Capacitor Selection
The input filter capacitor reduces peak currents drawn
from the power source and reduces noise and voltage
rippleꢀ onꢀ theꢀ inputꢀ causedꢀ byꢀ theꢀ circuit’sꢀ switching.ꢀ
Theꢀ inputꢀ capacitorꢀ RMSꢀ currentꢀ requirementꢀ (I
defined by the following equation:
(I
) of the inductor must be high enough to ensure that
SAT
saturation can occur only above the peak current-limit
value of 5.1A.
) is
RMS
Output Capacitor Selection
X7Rꢀceramicꢀoutputꢀcapacitorsꢀareꢀpreferredꢀdueꢀtoꢀtheirꢀ
stability over temperature in industrial applications. The
output capacitors are usually sized to support a step load
of 50% of the maximum output current in the application,
so the output voltage deviation is contained to 3% of the
output voltage change. The minimum required output
capacitance can be calculated as follows:
V
×(V - V
OUT
)
OUT
IN
I
= I
×
OUT(MAX)
RMS
V
IN
where, I
is the maximum load current. I
a maximum value when the input voltage equals twice
the output voltage (V = 2 x V ), so I
has
RMS
OUT(MAX)
=
RMS(MAX)ꢀ
IN
OUT
I
/2.
OUT(MAX)
I
× t
RESPONSE
1
2
STEP
Choose an input capacitor that exhibits less than +10°C
temperatureꢀ riseꢀ atꢀ theꢀ RMSꢀ inputꢀ currentꢀ forꢀ optimalꢀ
long-termꢀreliability.ꢀUseꢀlow-ESRꢀceramicꢀcapacitorsꢀwithꢀ
highꢀrippleꢀcurrentꢀcapabilityꢀatꢀtheꢀinput.ꢀX7Rꢀcapacitorsꢀ
are recommended in industrial applications for their
temperature stability. Calculate the input capacitance
using the following equation:
C
=
×
OUT
∆V
OUT
0.33
1
t
≅ (
+
)
RESPONSE
f
f
sw
C
where I
is the load current step, t
is the
STEP
RESPONSE
response time of the controller, DV
is the allowable
OUT
output voltage deviation, f is the target closed-loop
C
I
×D ×(1- D)
OUT(MAX)
C
=
crossover frequency, and f
is the switching frequency.
SW
IN
η× f
× ∆V
IN
SW
For the MAX17504, select f to be 1/9th of f
if the
C
SW
switchingꢀfrequencyꢀisꢀlessꢀthanꢀorꢀequalꢀtoꢀ500kHz.ꢀIfꢀtheꢀ
switchingꢀfrequencyꢀisꢀmoreꢀthanꢀ500kHz,ꢀselectꢀf to be
where D = V
/V is the duty ratio of the controller,
OUT IN
C
f ꢀisꢀtheꢀswitchingꢀfrequency,ꢀΔV is the allowable input
SW
IN
55kHz.ꢀForꢀtheꢀMAX17504S,ꢀselectꢀf to be 1/10th of f
C
SW
voltage ripple, and E is the efficiency.
ifꢀtheꢀswitchingꢀfrequencyꢀisꢀlessꢀthanꢀorꢀequalꢀtoꢀ1MHz.ꢀ
In applications where the source is located distant
from the MAX17504/MAX17504S input, an electrolytic
capacitor should be added in parallel to the ceramic
capacitor to provide necessary damping for potential
oscillations caused by the inductance of the longer input
power path and input ceramic capacitor.
Ifꢀtheꢀswitchingꢀfrequencyꢀisꢀmoreꢀthanꢀ1MHz,ꢀselectꢀf
toꢀbeꢀ100kHz.
C
Derating of ceramic capacitors with DC-voltage must be
considered while selecting the output capacitor. Derating
curvesꢀ areꢀ availableꢀ fromꢀ allꢀ majorꢀ ceramicꢀ capacitorꢀ
vendors.
Inductor Selection
Three key inductor parameters must be specified for
operation with the MAX17504/MAX17504S: inductance
V
IN
value (L), inductor saturation current (I
), and DC
SAT
R1
R2
resistanceꢀ (R
). The switching frequency and output
DCR
voltage determine the inductor value as follows:
EN/UVLO
V
f
OUT
SW
L =
SGND
where V
and f
are nominal values.
OUT
SW
Figure 1. Setting the Input Undervoltage Lockout
www.maximintegrated.com
Maxim Integrated │ 19
MAX17504
4.5V–60V, 3.5A, High-Efficiency, Synchronous
Step-Down DC-DC Converter
with Internal Compensation
capacitor (V
)ꢀtoꢀSGNDꢀ(seeꢀFigure 2). Connect the
Soft-Start Capacitor Selection
OUT
center node of the divider to the FB pin. Use the following
procedure to choose the resistive voltage-divider values:
CalculateꢀresistorꢀR3ꢀfromꢀtheꢀoutputꢀtoꢀFBꢀasꢀfollows:
TheꢀMAX17504/MAX17504Sꢀimplementsꢀadjustableꢀsoft-
start operation to reduce inrush current. A capacitor
connectedꢀ fromꢀ theꢀ SSꢀ pinꢀ toꢀ SGNDꢀ programsꢀ theꢀ
soft-start time. The selected output capacitance (C
)
SEL
3
216×10
and the output voltage (V
) determine the minimum
OUT
R3 =
required soft-start capacitor as follows:
f
× C
OUT
C
-6
C
ꢀ≥ꢀ28ꢀxꢀ10 x C
x V
SS
SEL OUT
whereꢀ R3ꢀ isꢀ inꢀ kI, crossover frequency f ꢀ isꢀ inꢀ kHz,ꢀ
C
The soft-start time (t ) is related to the capacitor
connected at SS (C ) by the following equation:
SS
and output capacitor C
is in µF. For the MAX17504,
OUT
SS
choose f to be 1/9th of the switching frequency, f , if
C
SW
-6
theꢀswitchingꢀfrequencyꢀisꢀlessꢀthanꢀorꢀequalꢀtoꢀ500kHz.ꢀ
t
= C /(5.55 x 10 )
SS
SS
Ifꢀtheꢀswitchingꢀfrequencyꢀisꢀmoreꢀthanꢀ500kHz,ꢀselectꢀf
C
For example, to program a 2ms soft-start time, a 12nF
capacitorꢀshouldꢀbeꢀconnectedꢀfromꢀtheꢀSSꢀpinꢀtoꢀSGND.
toꢀbeꢀ55kHz.ꢀForꢀtheꢀMAX17504S,ꢀselectꢀf to be 1/10th
C
of f
if the switching frequency is less than or equal
SW
toꢀ1MHz.ꢀIfꢀtheꢀswitchingꢀfrequencyꢀisꢀmoreꢀthanꢀ1MHz,ꢀ
Setting the Input Undervoltage Lockout Level
Theꢀ MAX17504/MAX17504Sꢀ offersꢀ anꢀ adjustableꢀ inputꢀ
undervoltage lockout level. Set the voltage at which
MAX17504/MAX17504S turns ON, with a resistive voltage-
select f ꢀtoꢀbeꢀ100kHz.
C
CalculateꢀresistorꢀR4ꢀfromꢀFBꢀtoꢀSGNDꢀasꢀfollows:
divider connected from V ꢀtoꢀSGND.ꢀConnectꢀtheꢀcenterꢀ
node of the divider to EN/UVLO.
ChooseꢀR1ꢀtoꢀbeꢀ3.3MIꢀandꢀthenꢀcalculateꢀR2ꢀasꢀfollows:
IN
R3 × 0.9
R4 =
(V
- 0.9)
OUT
R1×1.215
R2 =
(V
-1.215)
Table 2. C6 Capacitor Value at Various
Switching Frequencies
INU
where V
is the voltage at which the MAX17504/
INU
MAX17504S is required to turn ON. Ensure that V
is
INU
SWITCHING FREQUENCY RANGE (kHz)
C6 (pF)
2.2
higher than 0.8 x V . If the EN/UVLO pin is driven from
OUT
200 to 300
300 to 400
400 to 500
an external signal source, a series resistance of minimum
1kΩꢀ isꢀ recommendedꢀ toꢀ beꢀ placedꢀ betweenꢀ theꢀ signalꢀ
source output and the EN/UVLO pin, to reduce voltage
ringing on the line.
1.2
0.75
Loop Compensation
V
OUT
The MAX17504/MAX17504S is internally loop
compensated.ꢀHowever,ꢀifꢀtheꢀswitchingꢀfrequencyꢀisꢀlessꢀ
thanꢀ500kHz,ꢀconnectꢀaꢀ0402ꢀcapacitor,ꢀC6,ꢀbetweenꢀtheꢀ
CF pin and the FB pin. Use Table 2 to select the value
of C6.
R3
R4
FB
Adjusting Output Voltage
Set the output voltage with a resistive voltage-divider
connected from the positive terminal of the output
SGND
Figure 2. Setting the Output Voltage
www.maximintegrated.com
Maxim Integrated │ 20
MAX17504
4.5V–60V, 3.5A, High-Efficiency, Synchronous
Step-Down DC-DC Converter
with Internal Compensation
Power Dissipation
PCB Layout Guidelines
At a particular operating condition, the power losses that
lead to temperature rise of the part are estimated as
follows:
All connections carrying pulsed currents must be very
short and as wide as possible. The inductance of these
connections must be kept to an absolute minimum due to
the high di/dt of the currents. Since inductance of a current
carrying loop is proportional to the area enclosed by the
loop, if the loop area is made very small, inductance is
reduced. Additionally, small current loop areas reduce
radiated EMI.
1
2
P
= (P
×( - 1)) - I
×R
OUT DCR
LOSS
OUT
η
P
= V
×I
OUT
OUT OUT
where P
ofꢀ theꢀ converter,ꢀ andꢀ R
inductor. (See the Typical Operating Characteristics for more
information on efficiency at typical operating conditions).
isꢀ theꢀ totalꢀ outputꢀ power,ꢀ ηꢀ isꢀ theꢀ efficiencyꢀ
OUT
A ceramic input filter capacitor should be placed close to the
is the DC resistance of the
DCR
V
IN
pins of the IC. This eliminates as much trace inductance
effects as possible and give the IC a cleaner voltage supply.
A bypass capacitor for the V pin also should be placed
CC
close to the pin to reduce effects of trace impedance.
For a multilayer board, the thermal performance metrics
for the package are given below:
When routing the circuitry around the IC, the analog
small-signal ground and the power ground for switching
currents must be kept separate. They should be connected
together at a point where switching activity is at a
θ
= 30°C W
JA
θ
= 2°C W
JC
minimum, typically the return terminal of the V
bypass
CC
TheꢀjunctionꢀtemperatureꢀofꢀtheꢀMAX17504/MAX17504Sꢀ
can be estimated at any given maximum ambient
capacitor. This helps keep the analog ground quiet.
The ground plane should be kept continuous/unbroken
as far as possible. No trace carrying high switching
current should be placed directly over any ground plane
discontinuity.
temperature (T
) from the equation below:
A_MAX
T
= T
+ θ ×P
(
JA LOSS
)
J_MAX
A_MAX
If the application has a thermal management system
that ensures that the exposed pad of the MAX17504/
PCB layout also affects the thermal performance of the
design. A number of thermal vias that connect to a large
ground plane should be provided under the exposed pad
of the part, for efficient heat dissipation.
MAX17504S is maintained at a given temperature (T
EP_
)ꢀ byꢀ usingꢀ properꢀ heatꢀ sinks,ꢀ thenꢀ theꢀ junctionꢀ
MAX
temperature of the MAX17504/MAX17504S can be
estimated at any given maximum ambient temperature
from the equation below:
For a sample layout that ensures first pass success,
refer to the MAX17504 evaluation kit layout available at
www.maximintegrated.com.
T
= T
+ θ ×P
(
)
J_MAX
EP_MAX JC LOSS
Junctionꢀ temperatureꢀ greaterꢀ thanꢀ +125°Cꢀ degradesꢀ
operating lifetimes.
www.maximintegrated.com
Maxim Integrated │ 21
MAX17504
4.5V–60V, 3.5A, High-Efficiency, Synchronous
Step-Down DC-DC Converter
with Internal Compensation
Recommended Component Placement for MAX17504/MAX17504S
VOUT
PLANE
PGND PLANE
L1
LX PLANE
C1
C4
C5
LX PLANE
PGND PLANE
VIN PLANE
MAX17504/
MAX17504S
SGND
C2
R1
R2
MODE
R6
C3
C6
R3
R5
SGND PLANE
www.maximintegrated.com
Maxim Integrated │ 22
MAX17504
4.5V–60V, 3.5A, High-Efficiency, Synchronous
Step-Down DC-DC Converter
with Internal Compensation
V
IN
(7.5V TO 60V)
C1
2.2µF
C8
2.2µF
EN/UVLO
V
V
V
IN
IN
IN
BST
LX
C5
0.1µF
RT
V
OUT
5V, 3.5A
SYNC
MODE
L1
10µH
LX
C4
22µF
C9
22µF
MAX17504
R3
100kΩ
LX
V
CC
C2
FB
2.2µF
SGND
R4
22.1kΩ
RESET
CF SS
PGND PGND PGND
C3
12000pF
f
= 500kHz
SW
L1 = SLF12575T-100M5R4-H
C4, C9 = 22µF (MURATA GRM32ER71A226K)
Figure 3. MAX17504 Typical Application Circuit for 5V Output, 500kHz Switching Frequency
V
IN
(5.5V TO 60V)
C1
2.2µF
C8
2.2µF
EN/UVLO
V
V
V
IN
IN
IN
BST
LX
C5
0.1µF
RT
V
OUT
3.3V, 3.5A
SYNC
MODE
L1
6.8µH
LX
C4
22µF
C9
22µF
MAX17504
R3
82.5kΩ
LX
V
CC
C2
FB
2.2µF
SGND
R4
30.9kΩ
RESET
CF SS
PGND PGND PGND
C3
12000pF
f
= 500kHz
SW
L1 = MSS1048-682NL
C4, C9 = 22µF (MURATA GRM32ER71A226K)
Figure 4. MAX17504 Typical Application Circuit for 3.3V Output, 500kHz Switching Frequency
www.maximintegrated.com
Maxim Integrated │ 23
MAX17504
4.5V–60V, 3.5A, High-Efficiency, Synchronous
Step-Down DC-DC Converter
with Internal Compensation
V
IN
C1
2.2µF
R5
EN/UVLO
V
V
IN
IN
V
IN
RT
BST
C5
19.1KΩ
L1
4.7µH
V
OUT
0.1µF
5V,3.5A
SYNC
MODE
LX
LX
C4
22µF
R3
MAX17504S
115KΩ
LX
FB
V
CC
C2
2.2µF
R4
24.9KΩ
SGND
CF
RESET
PGND
SS
PGND
PGND
C3
12nF
f
= 1MHz
SW
L1 = 4.7µH (XAL6060, 6mm x 6mm)
C4 = 22µF (MURATA GRM32ER71A226K)
Figure 5. MAX17504S Typical Operating Circuit for 5V Output, 1MHz Switching Frequency
V
IN
C1
2.2µF
R5
EN/UVLO
V
V
IN
IN
V
IN
RT
BST
C5
19.1KΩ
L1
3.3µH
V
OUT
0.1µF
3.3V,3.5A
SYNC
MODE
LX
LX
C4
47µF
MAX17504S
R3
76.8KΩ
LX
FB
V
CC
C2
2.2µF
R4
28.7KΩ
SGND
CF
RESET
PGND
SS
PGND
PGND
C3
12nF
f
=
1MHz
L1 = 3.3µH (XAL6060, 6mm x 6mm)
C4 = 47µF (MURATA GRM32ER71A476KE15)
SW
Figure 6. MAX17504S Typical Operating Circuit for 3.3V Output, 1MHz Switching Frequency
www.maximintegrated.com
Maxim Integrated │ 24
MAX17504
4.5V–60V, 3.5A, High-Efficiency, Synchronous
Step-Down DC-DC Converter
with Internal Compensation
Ordering Information
PART
PIN-PACKAGE
MAX17504ATP+
MAX17504SATP+
20 TQFN-EP* 5mm x 5mm
20 TQFN-EP* 5mm x 5mm
Note: All devices operate over the temperature range of -40ºC
to +125ºC, unless otherwise noted.
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
Chip Information
PROCESS:ꢀBiCMOS
www.maximintegrated.com
Maxim Integrated │ 25
MAX17504
4.5V–60V, 3.5A, High-Efficiency, Synchronous
Step-Down DC-DC Converter
with Internal Compensation
Revision History
REVISION REVISION
PAGES
DESCRIPTION
CHANGED
NUMBER
DATE
11/13
2/14
0
1
2
Initial release
—
UpdatedꢀTOC32,ꢀTOC33,ꢀandꢀTypicalꢀApplicationꢀCircuitꢀfigures
9, 16, 17
1-17
10/16
AddedꢀMAX17504Sꢀtoꢀdataꢀsheet,ꢀupdatedꢀjunctionꢀtemperature,ꢀandꢀaddedꢀTOCs
Removedꢀ17504Sꢀfromꢀdataꢀsheet,ꢀcorrectedꢀpartꢀnumbersꢀinꢀGeneral Description,
Benefits and Features, Detailed Description, Operating Input Voltage Range sections,
updated TOCs 1a, 5, 5a, 6, 7a, 12, 12a, 13, 13a, 14a, 15a, 16a, 17a, 18a, 19a, 20a,
21a, 22, 22a, 23, 23a, 24a, 25a, 26a, 27a, 30a, 32a, Figures 3, 4, 5, and 6, removed
Recommended Component Placement for MAX17504/MAX17504S
3
5/17
1–26
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim
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 Character-
istics 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.
2017 Maxim Integrated Products, Inc.
│ 26
相关型号：
MAX17504ATP+T
Switching Regulator/Controller, Current-mode, 3.5A, 2450kHz Switching Freq-Max, BICMOS, PQCC20,
MAXIM
MAX17504SATP+
Switching Regulator, Current-mode, 5.85A, 2450kHz Switching Freq-Max, BICMOS, TQFN-20
MAXIM
MAX17505ATP+
Switching Regulator, Current-mode, 3.25A, 2450kHz Switching Freq-Max, BICMOS, TQFN-20
MAXIM
MAX17509ATJ+
Dual Switching Controller, 2200kHz Switching Freq-Max, BICMOS, 5 X 5 MM, ROHS COMPLIANT, TQFN-32
MAXIM
©2020 ICPDF网 联系我们和版权申明