MAX31910_V01 [MAXIM]
Ultra-Low Power Industrial, Octal, Digital Input Translator/Serializer;
| 型号： | MAX31910_V01 |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Ultra-Low Power Industrial, Octal, Digital Input Translator/Serializer |
| 文件： | 总19页 (文件大小：888K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
EVALUATION KIT AVAILABLE
MAX31910
Ultra-Low Power Industrial, Octal, Digital Input
Translator/Serializer
General Description
Benefits and Features
The MAX31910 industrial interface serializer translates,
conditions, and serializes the 24V digital output of sensors
and switches used in industrial, process, and building
automation to 5V CMOS-compatible signals required
by microcontrollers. It provides the front-end interface
circuit of a programmable logic controller (PLC) digital
input module.
● Ultra-Low Power and Heat Dissipation
• Low Quiescent Current (1.4mA typ)
• Highly Accurate and Stable Input Current Limiters,
Adjustable from 0.5mA to 6mA
• Special (Patent-Pending) Ultra-Low-Power Mode
with Switched Current Limiters
● High Integration Reduces BOM Count, Board
Size, and System Cost
The device features integrated current limiting, lowpass
filtering, and channel serialization. Input current limit-
ing allows a significant reduction in power consumed
from the field voltage supply as compared to traditional
discrete resistor-divider implementations. In addition, to
achieve the lowest in-class power dissipation, the device
uses patent-pending circuit techniques to achieve further
reduction of power beyond what is possible by input
current limiting alone.
• 8 High-Voltage Input Channels (36V max)
• On-Chip 8-1 Serialization with SPI Interface
• On-Chip 5V Regulator
• On-Chip Overtemperature Indicator
• On-Chip Field Supply Voltage Monitor
• Integrated Debounce Filters, Selectable from 0 to 3ms
● Robust Features and Performance for Industrial
Environments
• Multibit CRC Code Generation and Transmission for
Error Detection and More Reliable Data Transmission
• High ESD Immunity on All Field Input Pins
● Accepts Industry Standard Input Types
• Configurable for IEC 61131-2 Input Types 1, 2, and 3
● Flexible Power Supply Capability Enables Usage
in 5V, 12V, 24V, and Higher Voltage Systems
• Wide Operating Field Supply Range of 7V to 36V
• Can Be Powered From the Logic-Side Using a 5V
Supply
Selectable on-chip lowpass filters allow flexible debouncing
and filtering of sensor outputs based on the application.
On-chip serialization allows a drastic reduction in the
number of optocouplers used for isolation. The device
serializer is stackable so that any number of input channels
can be serialized and output through only one SPI-
compatible port. This reduces the number of optocouplers
needed to only three, regardless of the number of input
channels.
For enhanced robustness with respect to high-frequency
noise and fast electrical transients, a multibit CRC code
is generated and transmitted through the SPI port for
each 8 bits of data. The on-chip 5V voltage regulator can
be used to power external optocouplers, digital isolators,
or other external 5V circuitry.
Applications
● Digital Input Modules for PLCs
● Industrial, Building, and Process Automation
● Motor Control
For low-cost applications, Maxim Integrated offers a
pin-compatible version of this device, the MAX31911.
The MAX31911 does not include the patent-pending
current clamp-switching circuitry that is included with the
MAX31910.
The MAX31912 and MAX31913 versions includes energy-
less LED drivers while maintaining pin compatibility.
Ordering Information appears at end of data sheet.
19-6440; Rev 6; 8/17
MAX31910
Ultra-Low Power Industrial, Octal, Digital Input
Translator/Serializer
Block Diagram
24V
5V
5VOUT
V
5V REGULATOR
CC24V
MAX31910
VREF
SUPPLY
MONITOR
OR
FAULTB
TEMP
MONITOR
DB0
DB1
RIREF
SWITCHED
CURRENT
LIMITER
CRC GEN.
RT1
IN1
µCONTROLLER
OR
ISOLATION
LP
SENSORS
SIN
FILTER
MODESEL
CLK
VOLTAGE
COMPARATOR
VREF
SERIALIZER
CS
INPUT CHANNEL 0
RT8
IN8
SOUT
INPUT CHANNEL 7
GND
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MAX31910
Ultra-Low Power Industrial, Octal, Digital Input
Translator/Serializer
Absolute Maximum Ratings
(Voltages relative to GND.)
Operating Temperature Range
Ambient Temperature.............................-40NC to +125NC
Junction Temperature ............................-40NC to +150NC
Storage Temperature Range......................-55NC to +125NC
Lead Temperature (soldering, 10s) .........................+300NC
Soldering Temperature (reflow) ...............................+260NC
Voltage Range on V
Voltage Range on IN1–IN8 ............................ -0.3V to +45V
Voltage Range on IN1–IN8
(through 2.2kω resistors) ............................ -45V to +45V
Voltage Range on DB0/DB1, CLK, SIN,
............................. -0.3V to +45V
CC24V
CS, MODESEL .......................... -0.3V to (V
+ 0.3V)
5VOUT
Continuous Power Dissipation (T = +70NC)
A
TSSOP (derate 27mW/NC above +70NC).......... 2162.2mW
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional opera-
tion 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 Thermal Characteristics(Note 1)
TSSOP
Junction-to-Ambient Thermal Resistance (q ) ..........37°C/W
JA
Junction-to-Case Thermal Resistance (q )..................2°C/W
JC
Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer
board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial.
Recommended Operating Conditions (Note 2)
PARAMETER
Field Supply Voltage
Field Inputs Voltage
SYMBOL
CONDITIONS
MIN
7
TYP
MAX
36
UNITS
V
V
V
CC24V
V
(Note 3)
(Note 4)
-0.3
0
36
INn
LOGIC
Logic Inputs Voltage
Current-Limit Setting Resistor
Field Input Data Rate
V
5.5
V
R
15
kI
kHz
REF
f
200
IN
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MAX31910
Ultra-Low Power Industrial, Octal, Digital Input
Translator/Serializer
DC Electrical Characteristics
(V
= 7V to 36V, T = -40NC to +150NC, unless otherwise noted.) (Note 2)
J
CC24V
PARAMETER
Field-Supply Current
SYMBOL
CONDITIONS
MIN
TYP
MAX
2.2
UNITS
IN1–IN8 = 24V, 5VOUT = open,
RT1–RT8 = GND, all logic inputs open
I
1.4
mA
CC24V
Field-Supply UVLO Off/On
Field-Supply UVLO On/Off
V
9
8
10
V
V
ONUVLO
V
7
6
OFFUVLO
Field Input Threshold High-
to-Low
V
2.2kI external series resistor
7.5
8.5
1
V
V
V
V
IN-(INF)
IN+(INF)
HYS(INF)
Field Input Threshold Low-to-
High
2.2kI external series resistor (Note
11)
V
10
2.2kI external series resistor (Note
11)
Field Input Hysteresis
V
Input Threshold High-to-Low
(at IC pin)
V
2
2.5
TH-(INP)
TH+(INP)
HYS(INP)
Input Threshold Low-to-High
(at IC pin)
V
V
(Note 11)
(Note 11)
3.5
4
V
Input Threshold Hysteresis
(at IC pin)
1
V
Field Input Pin Resistance
Field Input Current Limit
R
0.8
2.4
kI
mA
INP
R
= 15kI, V
= 18V to 30V
REF
CC24V
I
2.2
2.6
INLIM
(Note 5)
DB1/DB0 = 0/0: no filtering
DB1/DB0 = 0/1
DB1/DB0 = 1/0
0
0.025
0.75
3
0.008
0.25
1.0
0.038
1.1
4.5
Filter Time Constant
t
ms
FILTER
DB1/DB0 = 1/1
Linear Regulator Output
Regulator Line Regulation
Regulator Load Regulation
Logic-Low Output Voltage
Logic-High Output Voltage
V
Max I
= 50mA
4.75
5.0
5.25
V
mV
mV
V
5VOUT
LOAD
dVREG
I
I
I
I
= 50mA
10
20
20
50
LINE
LOAD
LOAD
dVREG
= 1mA to 50mA
LOAD
V
= 4mA
0.4
1.0
OL
OL
V
= -4mA
4.0
V
OH
OH
0.3 x
0.5 x
0.7 x
Logic-Input Trip Point
V
V
IH-IL
V
V
V
5VOUT
-50
5VOUT
-30
5VOUT
-15
Logic-Input Leakage Current
Overtemperature Alarm
I
FA
NC
IL
T
135
ALRM
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MAX31910
Ultra-Low Power Industrial, Octal, Digital Input
Translator/Serializer
AC Electrical Characteristics
(V
= 7V to 36V, T = -40NC to +150NC, unless otherwise noted.) (Note 2)
CC24V
J
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Field Input Pulse Width
t
1
µs
No external capacitors on pins IN1-IN8
PW
HBM, all pins except IN1-IN8
±2
ESD
kV
HBM, IN1-IN8 with respect to GND
±15
AC Electrical Characteristics: SPI Interface
(V
= 7V to 36V, T = -40NC to +150NC, unless otherwise noted.) (Note 2)
J
CC24V
PARAMETER
SYMBOL
CONDITIONS
MIN
20
20
5
TYP
MAX
UNITS
ns
CLK Pulse Duration
t
(Note 6)
(Note 7)
(Note 8)
(Note 8)
(Note 9)
(Note 9)
(Notes 6, 10)
(Note 6)
(Note 7)
(Note 6)
CLKPW
t
ns
CS Pulse Duration
CSPW
SIN to CLK Setup Time
SIN to CLK Hold Time
t
ns
SU1
t
8
ns
H1
t
t
8
ns
CS to CLK Setup Time
SU2
12
ns
CS to CLK Recovery Time
Clock Pulse Frequency
REC
f
25
20
20
40
MHz
ns
CLK
Propagation Delay, CLK to SOUT
t
t
P1
ns
Propagation Delay, CS to SOUT
Rise/Fall Time SOUT/FAULT
P2
t
ns
R/F
Note 2: Limits are 100% production tested at T = +25°C and/or T = +125°C. Limits over the operating temperature range and
A
A
relevant supply voltage range are guaranteed by design and characterization. Typical values are not guaranteed.
Note 3: When using suggested external 2.2kω series resistors, limits of -3V to +36V apply.
Note 4:
f
refers to the maximum pulse frequency (1/f = shortest pulse width) that can be detected from the field sensors and
IN IN
switches.
Note 5: External resistor R
Note 6: See Figure 9.
Note 7: See Figure 6.
Note 8: See Figure 8.
Note 9: See Figure 7.
can be adjusted to set any desired current limit between 0.5mA and 6mA.
REF
Note 10: This is the maximum bit transfer rate through the serializer interface.
Note 11: When input current switching is enabled (DB0/DB1 = 0), there is no input threshold hysteresis. In this case, the input
threshold for both falling and rising signals is the high-to-low threshold.
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MAX31910
Ultra-Low Power Industrial, Octal, Digital Input
Translator/Serializer
Typical Operating Characteristics
(T = +25°C, R
= 15kω, unless otherwise noted.)
A
REF
POWER-SUPPLY CURRENT
CURRENT LIMIT vs. R
vs. V
FIELD SUPPLY
SUPPLY CURRENT vs. TEMPERATURE
REF
CC24V
1.60
1.55
1.50
1.45
1.40
1.35
1.30
1.60
1.55
1.50
1.45
1.40
5.5
4.5
3.5
2.5
1.5
0.5
0
10
20
R
30
40
5
15
25
35
-40
10
60
(kI)
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
REF
INPUT CURRENT LIMIT
vs. TEMPERATURE
INPUT CURRENT LIMIT
vs. FIELD INPUT VOLTAGE
INPUT VOLTAGE HYSTERESIS
vs. TEMPERATURE
3.0
2.9
2.8
2.7
2.6
2.5
2.4
2.3
2.2
2.1
2.0
3.0
2.5
2.0
1.5
1.0
0.5
0
4.0
3.8
3.6
3.4
3.2
3.0
2.8
2.6
2.4
2.2
2.0
V
= 24V
INn
V
= 24V
R
= 0I
CC24V
IN
OFF-ON THRESHOLD
ON-OFF THRESHOLD
-40
10
60
110
5
15
25
35
-40
10
60
110
AMBIENT TEMPERATURE (°C)
FIELD INPUT VOLTAGE (V)
TEMPERATURE (°C)
INPUT VOLTAGE HYSTERESIS
vs. TEMPERATURE
LDO LOAD REGULATION
LDO LINE REGULATION
9.0
8.8
8.6
8.4
8.2
7.0
7.8
7.6
7.4
7.2
7.0
5.10
5.08
5.06
5.04
5.02
5.00
4.98
4.96
4.94
4.92
4.90
5.10
5.08
5.06
5.04
5.02
5.00
4.98
4.96
4.94
4.92
4.90
R
= 2.2kI
I
= 5mA
IN
5VOUT
OFF-ON THRESHOLD
ON-OFF THRESHOLD
-40
10
60
110
0
10
20
30
40
50
6
11
16
21
26
31
36
TEMPERATURE (°C)
5VOUT OUTPUT CURRENT (mA)
SUPPLY VOLTAGE (V)
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MAX31910
Ultra-Low Power Industrial, Octal, Digital Input
Translator/Serializer
Typical Operating Characteristics (continued)
(T = +25°C, R
= 15kω, unless otherwise noted.)
A
REF
LDO OUTPUT
vs. V
FIELD SUPPLY
LDO LINE REGULATION
CC24V
5.10
5.5
5.4
5.3
5.2
5.1
5.0
4.9
4.8
4.7
4.6
4.5
I
= 50mA
I
= 50mA
5VOUT
5VOUT
5.08
5.06
5.04
5.02
5.00
4.98
4.96
4.94
4.92
4.90
6
11
16
21
26
31
36
4
14
24
34
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
LDO OUTPUT VOLTAGE
vs. TEMPERATURE
LDO OUTPUT VOLTAGE
vs. TEMPERATURE
5.10
5.08
5.06
5.04
5.02
5.00
4.98
4.96
4.94
4.92
4.90
5.10
5.08
5.06
5.04
5.02
5.00
4.98
4.96
4.94
4.92
4.90
I
= 0mA
I
= 5mA
5VOUT
5VOUT
-40
10
60
110
-40
10
60
110
AMBIENT TEMPERATURE (°C)
AMBIENT TEMPERATURE (°C)
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MAX31910
Ultra-Low Power Industrial, Octal, Digital Input
Translator/Serializer
Pin Configuration
TOP VIEW
ꢀ
DB0
1
2
28
27
26
25
24
23
22
21
20
19
18
17
16
15
GND
SIN
DB1
IN1
RT1
IN2
RT2
IN3
3
MODESEL
CLK
4
CS
5
SOUT
6
MAX31910
7
IN8
RT3
IN4
8
RT8
9
IN7
RT4
10
11
12
13
14
RT7
IN5
IN6
RT5
RT6
RIREF
CC24V
FAULT
5VOUT
EP
V
Pin Description
PIN
NAME
FUNCTION
Debounce (Filtering) Time Select Inputs. These inputs also determine the current
switching frequency. See Table 1 for details.
1, 2
DB0, DB1
IN1–IN8
3, 5, 7, 9, 11, 18,
20, 22
Field Inputs
4, 6, 8, 10, 12,
17, 19, 21
Connect directly to GND. These pins are reserved for energy-less LED drivers in future
versions of the device.
RT1–RT8
RIREF
13
14
15
16
23
24
25
Current-Limiter Reference Resistor
Field-Supply Voltage
V
CC24V
5VOUT
5V Regulator Output
Open-Drain Output. Active-low for overtemperature/undervoltage conditions.
Serial-Data Out
FAULT
SOUT
Active-Low Chip-Select Input
Serial-Clock Input
CS
CLK
Mode-Select Input
26
MODESEL
MODESEL = 1: Selects 8-bit shift register
MODESEL = 0: Selects 16-bit shift register
27
28
—
SIN
GND
EP
Serial-Data Input
Field Ground
Exposed Pad. Must be connected to the PCB ground plane.
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MAX31910
Ultra-Low Power Industrial, Octal, Digital Input
Translator/Serializer
Basic Application Circuit
JUMPERS TO
5VOUT
AND GND
24V
R1
5VOUT
V
CC24V
C1
DB0
DB1
C4
MODESEL
SIN
VDD_LOGIC
MAX31910
R
INX
CLK
CLK
f
IN1–8
IN1–8
CS
SOUT
CS
ISOLATION
SOUT
RT1–8
FAULT
FAULT
RIREF
GND
R
REF
NOTE: SEE FIGURE 1 FOR ADDITIONAL COMPONENTS NEEDED FOR EMC.
Glitch Filter
Detailed Description
A digital glitch filter provides debouncing and filtering
of noisy sensor signals. The time constant of this filter is
programmable from 0ms to 3ms through the DB0 and
DB1 pins. See Table 1 for debounce settings.
Input Current Clamp
The MAX31910 industrial interface serializer inputs (IN1–
IN8) sense the state (on vs. off) of field sensors by moni-
toring both voltage and current flowing through the sen-
sor output. The current sinking through these input pins
rises linearly with input voltage until the limit set by the
current clamp is reached. Any voltage increase beyond
this point does not increase the input current any further.
To provide the digital glitch filter, the device checks that
an input is stable for at least three clock cycles. The dura-
tion of a clock cycle is 1/3 of the selected debounce time.
If the input is not stable for at least three clock cycles,
the input change is not sent to the internal shift register.
The value of the current clamp is adjustable through an
external resistor connected between the RIREF pin and
GND. Pins RT1–RT8 must be connected directly to GND
to provide a return path for the input current. The volt-
age and current at the IN1–IN8 input pins are compared
against internally set references to determine whether the
sensor is on (logic 1) or off (logic 0). The trip points deter-
mining the on/off status of the sensor satisfy the require-
ments of IEC 61131-2 Type 1 and 3 switches. The device
can also be configured to work as a Type 2 switch.
Low-Power Current Clamp Switching
The MAX31910 uses a patent-pending switched cur-
rent limiter to reduce power consumption below what is
achievable by current limiting alone (Figure 1). The inter-
nal filter clock is used to switch input current between
100% and 20% of the chosen current limit. For example,
if the current limit is set to 2.4mA, the input current
switches between 2.4mA and 0.48mA. The switching is
done at a controlled ramp rate of t
(0.5µs typ). The
DELAY
filter clock switches input current at a 50% duty cycle.
The clock period for current switching is automatically
selected by the DB1 and DB0 glitch filter settings. See
Table 1 for current switching settings.
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MAX31910
Ultra-Low Power Industrial, Octal, Digital Input
Translator/Serializer
24V
SENSOR OUTPUT VOLTAGE
t
t
DELAY
DELAY
0V
100% I
20% I
LIMIT
INPUT CURRENT LIMIT
LIMIT
INTERNAL FILTER CLOCK
TIME
COMPARATOR OUTPUT IS LATCHED INTO FILTER ON
RISING EDGE OF CLOCK
Figure 1. Operation of Patent-Pending Switched Current Limiter
Table 1. Debounce Settings
DB1
DB0
BINARY VALUE
DEBOUNCE TIME
CURRENT SWITCHING PERIOD
0
0
1
1
0
1
0
1
0
1
2
3
0
DC (disabled)
8Fs
25Fs
0.75ms
3ms
0.25ms
1ms
Powering the Device Through the 5VOUT Pin
Reading Serial Data
The device can alternatively be powered using a 5V
supply connected to the 5VOUT pin. In this case a 24V
supply is no longer needed and the VCC24V supply must
be kept unconnected (see Figure 2).
The filtered outputs of the input comparators are latched
into a shift register at the falling edge of CS. Clocking the
CLK pin, while CS is held low, shifts the latched data out
of SOUT 1 bit at a time.
In this configuration, the device will always indicate
a UVFAULT and the FAULT pin will always be active
(pulled low). Faults due to the supply voltage monitoring
will not be available. Faults due to the temperature monitor
can only be read through the SPI interface.
The internal data serializer comprises a 16-bit shift register,
containing 8 bits of data corresponding to the eight field
inputs, as well as an 8-bit status byte containing supplementary
status and CRC information. The status byte contains 1 bit
representing the status of the field-supply voltage (UV),
1 bit representing the status of the internal temperature
monitor (OT), a 5-bit CRC code internally calculated and
generated, and a trailing 1 as a STOP bit.
This configuration has a lower power consumption and
heat dissipation since the on-chip 5V voltage regulator
is disabled.
The undervoltage (UV) bit is normally 0. If the supply
voltage falls below V
, the UV becomes a 1. The
OFFUVLO
UV bit returns to 0 once the supply voltage has returned
above V
.
ONUVLO
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MAX31910
Ultra-Low Power Industrial, Octal, Digital Input
Translator/Serializer
JUMPERS TO
5V AND GND
5V
NOT
CONNECTED
5VOUT
DB0
VCC24V
DB1
MODESEL
C1
C3
SIN
MAX31910
RINX
FIN1-8
IN1-8
CLK
CS
SOUT
RT1-8
FAULT
RIREF
GND
RREF
Figure 2. Basic Application Powered Through 5VOUT
The overtemperature (OT) bit is also normally 0. If the
junction temperature increases to above T , the OT
next device, effectively cascading the internal shift
registers. TheCLKandCS pinsofallthedevicesshouldbe
connected together in this configuration. See the Serial-
Port Operation section for more detailed information on
operating the SPI interface.
ALRM
bit becomes a 1. The bit returns to 0 once the junction
temperature has returned below T
.
ALRM
The CRC code can be used to check data integrity during
transfer from the device to an external microcontroller. In
applications where the integrity of data transferred is not
of concern, the CRC bits can be ignored. The CRC uses
the following polynomial:
Temperature Monitoring
The internal junction temperature of the device is con-
stantly monitored. An alarm is raised, by asserting the
FAULT pin, if the temperature rises above T
addition to asserting FAULT, the device sets the OT bit
. In
ALRM
P(x) = x5 + x4 + x2 + x0
to a 1.
The number of bits in the internal serializer can be select-
ed between 8 bits or 16 bits. The MODESEL pin is used
to configure the serializer as an 8-bit (disabling the status
byte) or 16-bit shift register. In 8-bit mode, only the eight
field input states are transferred through the SPI port and
the status byte is ignored. Therefore, in multiple IC appli-
cations (input channels greater than 8), if desired, only a
single status byte can be generated and transmitted for
any number of input channels.
Supply Voltage Monitoring
A supply voltage monitor circuit constantly monitors
the field-supply voltage. If this voltage falls below a
threshold (V
), an alarm is raised by asserting
OFFUVLO
the FAULT pin, indicating that the part is experiencing
a fault condition and the data in the serializer is not to
be trusted. In addition, the device sets the UV bit to a 1.
Once the field-supply voltage has recovered and goes
above V
normal operation of the part.
The shift register contents are read only (no write capa-
bility exists) through the SPI-compatible interface.
, the FAULT pin is released, indicating
ONUVLO
For higher input counts than 8, multiple devices can
be cascaded. In this case, the SOUT pin of one
device should be connected to the SIN pin of the
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MAX31910
Ultra-Low Power Industrial, Octal, Digital Input
Translator/Serializer
Daisy-Chain Operation
Applications Information
For systems with more than eight sensor inputs, multiple
devices can be daisy-chained to allow access to all data
EMC Standards Compliance
The external components shown in Figure 3 allow the
device to operate in harsh industrial environments.
Components were chosen to assist in suppression of
voltage burst and surge transients, allowing the system
to meet or exceed international EMC requirements.
Table 2 lists an example device for each component
in Figure 3. The system shown in Figure 3, using the
components shown in Table 2, is designed to be robust
against IEC Fast Transient Burst, surge, conducted RFI
specifications, and ESD specifications (IEC 61000-4-2,
-4, -5, and -6).
inputs through a single serial port. When using a daisy-
chain configuration, connect SOUT of one of the devices
to the SIN input of another upstream device. CS and SCK
of all devices in the chain should be connected together
in parallel (see Figure 4).
In a daisy-chain configuration, external components
used to enhance EMC robustness do not need to be
duplicated for each device of a circuit board. Figure 5
illustrates a 16-input application.
SPI Waveforms
The serial output of the device adheres to the SPI proto-
col, running with CPHA = 0 and CPOL = 0. Input states
on IN1–IN8 are latched in on the falling edge of CS. The
transfer of data out of the slave output, SOUT, starts
immediately when CS is asserted (i.e., MSB is output
onto SOUT independent of CLK). The remaining data bits
are shifted out on the falling edge of CLK. The data bits
are written to the output SOUT with MSB first. When CS
is high, SOUT is high impedance. The resultant timing is
shown in Figure 6. Note that all bits after IN1 are invalid
if 8-bit operation mode is selected with the MODESEL
input. Figure 7, Figure 8, Figure 9, and Figure 10 illustrate
SPI timing specifications.
Serial-Port Operation
Serial output of the device functions in one of two modes,
depending on the MODESEL setting (Table 3).
With MODESEL = 0, the device output includes a 5-bit
CRC, an undervoltage alarm, and an overtemperature
alarm. See the Detailed Description for CRC, undervolt-
age, and overtemperature functional descriptions.
With MODESEL = 1, the device outputs only the state
of the IN1–IN8 inputs and omits the CRC, undervoltage
alarm, and overtemperature alarm.
Table 2. Recommended Circuit Components
COMPONENT
DESCRIPTION
4.7nF, 2kV polypropylene capacitor
10FF, 60V ceramic capacitor
REQUIRED/RECOMMENDED/OPTIONAL
Recommended
C0
C1
C3
C4
C5
D0
D1
R1
Required
100nF, 10V ceramic capacitor
Recommended
4.7µF, 10V low ESR ceramic capacitor
100nF, 100V ceramic capacitor
36V fast zener diode (ZSMB36)
General-purpose rectifier (IN4007)
Required
Recommended
Recommended
Optional: For reverse-polarity protection.
Recommended
150I, 1/3W MELF resistor
2.2kI, 1/4W MELF resistor
15kI, 1/8W resistor
R
Required
INX
R
Required
REF
Note: For higher EFT performance, a minimum 1nF, 1000V capacitor can be added from nodes f –f
additional methods to improve EFT robustness, please check the Maxim website regularly for upcoming application notes currently
being developed.
to earth or ground. For
IN1 IN8
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MAX31910
Ultra-Low Power Industrial, Octal, Digital Input
Translator/Serializer
JUMPERS TO
5VOUT
AND GND
24V
D1
C1
R1
5VOUT
V
CC24V
C0
D0
C5
DB0
DB1
C3
C4
EARTH
VDD_LOGIC
CLK
MODESEL
SIN
MAX31910
R
INX
CLK
f
IN1–8
IN1–8
CS
CS
ISOLATION
SOUT
SOUT
RT1–8
FAULT
FAULT
RIREF
GND
R
REF
FIELD
GROUND
C0
0V
EARTH
Figure 3. Typical EMC Protection Circuitry
SIN
SIN
SIN
MAX31910
MAX31910
MAX31910
SOUT
SOUT
SOUT
TO µCONTROLLER
Figure 4. Daisy-Chain Operation
Table 3. MODESEL Settings
MODESEL SETTING
FUNCTIONALITY
0
1
16-bit output; [IN8–IN1][CRC (5 bit)][UV][OT][0]
8-bit output; [IN8–IN1]
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MAX31910
Ultra-Low Power Industrial, Octal, Digital Input
Translator/Serializer
JUMPERS TO
5VOUT
AND GND
24V
R1
5VOUT
V
CC24V
C0
D0
C1
DB0
DB1
C3
C4
MODESEL
EARTH
VDD_LOGIC
MAX31910
SIN
R
INX
CLK
CLK
f
IN1–8
IN1–8
CS
SOUT
CS
ISOLATION
SOUT
FAULT
RT1–8
RIREF
FAULT
GND
R
REF
D1
C0
0V
EARTH
CLK
V
CC24V
C1
CS
SOUT
FAULT
SIN
JUMPERS TO
5VOUT
AND GND
MAX31910
R
INX
IN1–8
f
IN1–8
5VOUT
DB0
DB1
C3
C4
RT1–8
RIREF
MODESEL
GND
R
REF
Figure 5. 16-Input Application Circuit
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MAX31910
Ultra-Low Power Industrial, Octal, Digital Input
Translator/Serializer
CLK
IN8
IN7
IN6
IN5
IN4
IN3
IN2
IN1
CRC4
CRC3
CRC2
CRC1
CRC0
UV
OT
0
SOUT
CS
IN8–IN1 VALID
Figure 6. SPI Communication Example
t
t
P2
CSPW
t
t
H1
SU1
CS
CLK
SIN
SIN VALID
SOUT
Figure 7. SPI Timing Diagram 1
Figure 9. SPI Timing Diagram 3
1/f
CLK
t
CSPW
t
t
REC
SU2
CS
CS
t
R/F
SOUT
CLK
t
P1
t
R/F
Figure 8. SPI Timing Diagram 2
Figure 10. SPI Timing Diagram 4
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MAX31910
Ultra-Low Power Industrial, Octal, Digital Input
Translator/Serializer
Chip Information
PROCESS: S45JRS
Package Information
For the latest package outline information and land patterns
(footprints), go to www.maximintegrated.com/packages. Note
that a “+”, “#”, or “-” in the package code indicates RoHS status
only. Package drawings may show a different suffix character,
but the drawing pertains to the package regardless of RoHS status.
Ordering Information
PACKAGE
TYPE
PACKAGE
CODE
OUTLINE
NO.
LAND
PATTERN NO.
PIN-
PACKAGE
PART
TEMP RANGE
CARRIER
28 TSSOP-EP
U28E+4
MAX31910AUI+
MAX31910AUI+T
-40NC to +125NC 28 TSSOP
Bulk
Tape
and Reel
-40NC to +125NC 28 TSSOP
+Denotes a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
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MAX31910
Ultra-Low Power Industrial, Octal, Digital Input
Translator/Serializer
Revision History
REVISION
NUMBER
REVISION
DATE
PAGES
DESCRIPTION
CHANGED
0
8/12
Initial release
—
Changed the supply voltage minimum from 10V to 7V; changed the current
limits in the EC table Note 5; added a new Figure 1 to show current-limit
switching; added the CRC polynomial to the Reading Serial Data section
1
9/12
1-4, 9
Updated Block Diagram, TOCs 4, 5, 8–10, Input Current Clamp, Low-Power
Current Clamp Switching, Basic Application Circuit, and EMC Standards
Compliance sections, Table 2, and Figures 2, 4, and 5
2
11/13
1, 5, 6, 8, 10–13
Added Note 11 to DC Electrical Characteristics table, deleted portion of
Table 2 note.
3
4
5
7/14
2/15
4/15
3, 4, 11
1
Updated front page content
Correct errata in General Description, added powering from 5VOUT,
corrected errata in figures, errata in Electrical Characteristics table.
1, 3, 5, 8, 10, 12-
13, 15
Updated Electrical Characteristics and Pin Description tables, Typical
Operating Characteristics section, and Table 3
6
8/17
5, 6, 8, 13
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.
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.
2017 Maxim Integrated Products, Inc.
│ 17
MAX31910
Ultra-Low Power Industrial, Octal, Digital Input
Translator/Serializer
Maxim Integrated
│ 18
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MAX31910
Ultra-Low Power Industrial, Octal, Digital Input
Translator/Serializer
Maxim Integrated
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