General Description
The MAX4896 8-channel relay and load driver is designed
for medium voltage applications up to 50V. This device is
offered in a 20-pin, 5mm x 5mm TQFN package, resulting
in substantial board space savings.
The MAX4896 8-channel relay driver offers built-in induc-
tive kickback protection, drive for latching/nonlatching
or dual-coil relays, and open-load and short-circuit fault
detection.The MAX4896 also protects against overcur-
rent conditions. Each independent open-drain output fea-
tures a 3Ω (typ) on-resistance, and is guaranteed to sink
200mA of load current (VS ≥ 4.5V).
A built-in overvoltage protection clamp handles kickback-
voltage transients, which are common when driving induc-
tive loads. Thermal-shutdown circuitry shuts off all outputs
(OUT_) when the junction temperature exceeds +160°C.
The MAX4896 employs a reset input that allows the user to
turn off all outputs simultaneously with a single control line.
The MAX4896 includes a 10MHz SPI™-/QSPI™-/
MICROWIRE™-compatible serial interface. The serial inter-
face is compatible with TTL-/CMOS-logic voltage levels and
operates with a single +2.7V to +5.5V supply. In addition,
the SPI output data can be used for diagnostics purposes
including open-load and shortcircuit fault detection.
The MAX4896 is offered in the extended (-40°C to +85°C) and
automotive (-40°C to +125°C) operating temperature ranges.
Features
● Supports Up to 50V Continuous Drain-to-Source
Voltage
● Guaranteed Drive Current:
• VS ≥ 4.5V
200mA (All Channels On)
410mA (Individual Channels)
• VS ≤ 3.6V
100mA
● Built-In Output Clamp Protects Against Inductive
Kickback
● +2.7V to +5.5V Logic Supply Voltage
●RESET Input Turns Off All Outputs Simultaneously
● Built-in Power-On Reset
● Automotive Temperature Range (-40°C to +125°C)
● SPI-/QSPI-/MICROWIRE-Compatible Serial Interface
● Serial Digital Output for Daisy Chaining and
Diagnostics
●FLAG Output for μP Interrupt
●Open-Load and Short-Circuit Detection and Protection
●Thermal Shutdown
● Low 100μA (max) Quiescent Supply Current
● Space-Saving, 5mm x 5mm, 20-Pin TQFN Package
Applications
SPI and QSPI are trademarks of Motorola, Inc.
MICROWIRE is a trademark of National Semiconductor Corp.
● Industrial Equipment
● White Goods
●Power-Grid Monitoring
and Protection Equipment
●ATE
Pin Configuration appears at end of data sheet.
*EP = Exposed pad.
+Denotes lead(Pb)-free/RoHS-compliant package.
PART TEMP RANGE PIN-PACKAGE
MAX4896ETP+ -40°C to +85°C 20 TQFN-EP*
(5mm x 5mm)
MAX4896ATP+ -40°C to +125°C 20 TQFN-EP*
(5mm x 5mm)
MAX4896
OUT8
SCLK
CS
DIN
RESET
DOUT
PGNDGNDSLPD
VCC = 2.7V TO 5.5V
0.1µF
VS
RELAY
COIL 8
OUT1
PDCD
VRELAY
VRELAY
FLAG
µC
INT
RELAY
COIL 1
MAX4896 Space-Saving, 8-Channel Relay/Load Driver
19-3843; Rev 4; 5/14
Typical Operating Circuit
Ordering Information
(All voltages referenced to GND.)
VS .........................................................................-0.3V to +7.0V
OUT_ .................................................................. (-0.3V to +50V)
Continuous OUT_ Voltage .................................................+50V
CS, SCLK, DIN, RESET, SPLD, PDCD ............... -0.3V to +7.0V
DOUT ..........................................................-0.3V to (VS + 0.3V)
PGND to GND ................................................... (-0.3V to +0.3V)
Continuous OUT_ Current, TA = +25°C (Note 1)
All Outputs On ..............................................................210mA
Single Output On .......................................................... 420mA
Continuous Power Dissipation (TA = +70°C)
20-Pin TQFN (derate 21.3mW/°C above +70°C) .....1702mW
Maximum Output Clamp Energy (EOUT_) .......................... 30mJ
Operating Temperature Range ......................... -40°C to +125°C
Junction Temperature ...................................................... +150°C
Storage Temperature Range ............................ -65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow) ....................................... +260°C
20 TQFN-EP
Junction-to-Ambient Thermal Resistance (θJA) ..........29°C/W Junction-to-Case Thermal Resistance (θJC) .................2°C/W
(Note 2)
(VS = +2.7V to +5.5V, TA = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 3)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Operating Voltage VS2.7 5.5 V
Quiescent Current ICC IOUT_ = 0, logic inputs = 0 or
VS, RESET = low
VS = 3.6V 5 70 μA
VS = 5V 10 100
Dynamic Average Supply
Current IS
fSCLK = 10MHz, fDIN = 0.5 x fCLK,
COUT = 50pF, VS = 5.5V 6 mA
Thermal Shutdown TSHD +160 °C
Thermal-Shutdown Hysteresis TSHDH 20 °C
Power-On Reset VRST VS falling 1.8 2.05 2.3 V
Power-On-Reset Hysteresis VRSTH 140 mV
DIGITAL INPUTS (SCLK, DIN, CS, RESET, PDCD, SPLD)
Input Logic-High Voltage VIH
VS = 2.7V to 3.6V 2.0
V
VS = 4.5V to 5.5V 2.4
Input Logic-Low Voltage VIL
VS = 2.7V to 3.6V 0.6
V
VS = 4.5V to 5.5V 0.8
Input Logic Hysteresis VHYST 230 mV
Input Leakage Currents ILEAK Input voltages = 0 or +5.5V -1 +1 µA
Input Capacitance CIN 10 pF
MAX4896 Space-Saving, 8-Channel Relay/Load Driver
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Note 1: Maximum continuous current at a given temperature must be calculated such that the maximum continuous power dissipation
for the package is not exceeded.
Note 2: 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.
Absolute Maximum Ratings
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 Thermal Characteristics
Electrical Characteristics
(VS = +2.7V to +5.5V, TA = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 3)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
RELAY OUTPUT DRIVERS (OUT1–OUT8)
OUT_ ON Resistance RON
IOUT = 50mA,
VS = 2.7V
TJ = +25°C 5 6
Ω
TJ = +125°C 11
TJ = +150°C 12
IOUT = 100mA,
VS = 4.5V
TJ = +25°C 3 4
TJ = +125°C 7
TJ = +150°C 8
IOUT Off-Leakage Current ILEAK PDCD = high or RESET = low, all outputs Off -1 +1 μA
OUT Clamping Voltage VCLAMP (Note 4) 50 75 V
OUT Current-Limit Threshold ILIM VS ≥ 4.5V 400 960 mA
OUT Capacitance VOUT = 16V, f = 1MHz 30 pF
DIAGNOSTIC
Open-Load Detection Voltage
Threshold VDS(OL) OUT_ falling 0.75 1 1.15 V
Open-Load Detection-Voltage-
Threshold Hysteresis VDS(OLH) 40 mV
OUT_ Pulldown Current IPD(OL) PDCD = low 150 300 500 µA
Fault Delay/Filtering Time tD(FAULT) From rising edge at CS at 50% to valid
diagnostic data 30 90 280 µs
DIGITAL OUTPUT (DOUT, FLAG)
DOUT Low Voltage VOL
2.7V ≤ VS ≤ 3.6V, ISINK = 0.3mA 0.4 V
4.5V ≤ VS ≤ 5.5V, ISINK = 0.5mA 0.4
DOUT High Voltage VOH
2.7V ≤ VS ≤ 3.6V, ISOURCE = 0.25mA VS - 0.5 V
4.5V ≤ VS ≤ 5.5V, ISOURCE = 0.4mA VS - 0.5
FLAG Low Voltage ISINK = 0.5mA 0.4 V
FLAG Off-Leakage Current 4.5V ≤ VS ≤ 5.5V, VFLAG = 5.5V -1 +1 μA
TIMING
Turn-On Time (OUT_) tON
From rising edge of CS at 50% to
VOUT_ = 90%VP, VP = 15V, RL = 300Ω,
CL = 50pF, 2.7V ≤ VS < 3.6V
20
μs
From rising edge of CS at 50% to
VOUT_ = 90%VP, VP =16V, RL = 150Ω,
CL = 50pF, 4.5V ≤ VS ≤ 5.5V
10
Turn-Off Time (OUT_) tOFF
From rising edge of CS at 50% to
VOUT_ = 10%VP, VP = 15V, RL = 300Ω,
CL = 50pF, 2.7V ≤ VS < 3.6V
15
μs
From rising edge of CS at 50% to
VOUT_ = 90%VP, VP = 16V, RL = 150Ω,
CL = 50pF, 4.5V < VS ≤ 5.5V
10
MAX4896 Space-Saving, 8-Channel Relay/Load Driver
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Electrical Characteristics (continued)
(VS = +2.7V to +5.5V, TA = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 3)
Note 3: Specifications at -40°C are guaranteed by design and not production tested.
Note 4: The output stages are compliant with the transient immunity requirements, as specified in ISO 7637 Part 3 with test pulses
1, 2, 3a, and 3b.
Note 5: Guaranteed by design.
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
SCLK Frequency fSCLK
TA = +85°C 2.7V ≤ VS < 3.6V 0 6
MHz
4.5V ≤ VS ≤ 5.5V 11
TA = +125°C 2.7V ≤ VS ≤ 3.6V 0 5
4.5V ≤ VS ≤ 5.5V 10
Cycle Time tCH + tCL
2.7V ≤ VS ≤ 3.6V 200
ns
4.5V ≤ VS ≤ 5.5V 100
CS Fall-to-SCLK Rise Setup tCSS
2.7V ≤ VS ≤ 3.6V 100 ns
4.5V ≤ VS ≤ 5.5V 50
CS Rise-to-SCLK Hold tCSH
2.7V ≤ VS ≤ 3.6V 100 ns
4.5V ≤ VS ≤ 5.5V 50
SCLK High Time tCH
2.7V ≤ VS ≤ 3.6V 80
ns
4.5V ≤ VS ≤ 5.5V 40
SCLK Low Time tCL
2.7V ≤ VS ≤ 3.6V 80
ns
4.5V ≤ VS ≤ 5.5V 40
Data Setup Time tDS
2.7V ≤ VS ≤ 3.6V 40
ns
4.5V ≤ VS ≤ 5.5V 20
Data Hold Time tDH
2.7V ≤ VS ≤ 3.6V 5
ns
4.5V ≤ VS ≤ 5.5V 0
SCLK Fall-to-DOUT Valid tDO
50% of SCLK to 20% of
VS falling edge,
CL = 50pF, 50% at
SCLK to 80% of VS
rising edge
2.7V ≤ VS ≤ 3.6V 70
ns
4.5V ≤ VS ≤ 5.5V 30
Rise Time (DIN, SCLK, CS,
RESET)tSCR 20% of VS to 70% of
VS, CL = 50pF (Note 5)
2.7V ≤ VS ≤ 3.6V 2
μs
4.5V ≤ VS ≤ 5.5V 2
Fall Time (DIN, SCLK, CS,
RESET)tSCF 20% of VS to 70% of
VS, CL = 50pF (Note 5)
2.7V ≤ VS ≤ 3.6V 2
μs
4.5V ≤ VS ≤ 5.5V 2
RESET Min Pulse Width tRW 70 ns
MAX4896 Space-Saving, 8-Channel Relay/Load Driver
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Electrical Characteristics (continued)
(TA = +25°C, unless otherwise noted.)
fCLK (MHz)
SUPPLY CURRENT vs. fCLK
MAX4896 toc02
SUPPLY CURRENT (mA)
3.0
3.5
4.0
4.5
5.0
5.5
6.0
2.5
2.0
0.1 1 10
VS = 5V
VS = 2.7V
VS = 3.3V
fDIN = 0.5 x fCLK
ON-RESISTANCE
vs. SUPPLY VOLTAGE
MAX4896 toc03
SUPPLY VOLTAGE (V)
RON (Ω)
5.14.73.9 4.33.53.1
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
IOUT_SINK = 100mA
2.0
2.7 5.5
IOUT_SINK = 50mA
MAX4896 toc04
TEMPERATURE (°C)
RON (Ω)
1109580655035205-10-25
2
3
4
5
6
7
8
IOUT_SINK = 50mA
1
-40 125
ON-RESISTANCE
vs. TEMPERATURE
VS = 2.7V
VS = 5V
VS = 5.5V
VS = 3.3V
ON-RESISTANCE
vs. TEMPERATURE
MAX4896 toc05
TEMPERATURE (°C)
RON (Ω)
1109580655035205-10-25
2
3
4
5
6
7
8
VS = 2.7V
1
-40 125
VS = 3.3V
VS = 5V
VS = 5.5V
IOUT_SINK = 100mA
POWER-ON RESET VOLTAGE
vs. TEMPERATURE
MAX4896 DS toc06
TEMPERATURE (°C)
POWER-ON-RESET VOLTAGE (V)
1109580655035205-10-25
2.02
2.04
2.06
2.08
2.10
2.12
2.14
2.00
-40 125
OUTPUT OFF LEAKAGE CURRENT
vs. SUPPLY VOLTAGE
MAX4896 toc07
SUPPLY VOLTAGE (V)
OUTPUT OFF LEAKAGE (pA)
5.14.73.9 4.33.53.1
10
20
30
40
50
60
70
80
90
100
VOUT = 50V
0
2.7 5.5
VOUT = 24V
VOUT = 12V
QUIESCENT CURRENT
vs. SUPPLY VOLTAGE
MAX4896 toc01
SUPPLY VOLTAGE (V)
QUIESCENT CURRENT (µA)
5.14.73.9 4.33.53.1
1
2
3
4
5
6
7
8
9
10
11
12
0
2.7 5.5
TA = +125°C
ALL LOGIC INPUTS = VS
TA = +25°C
TA = -40°C
TA = +85°C
TEMPERATURE (°C)
OUT LEAKAGE CURRENT (nA)
OUT LEAKAGE CURRENT
vs. TEMPERATURE
100
PDCD = VS
10
1
0.1
0.01
0.001
1109580655035205-10-25-40 125
MAX4896 DS toc08
VOUT = 50V
VOUT = 12V
VOUT = 24V
INPUT LOGIC THRESHOLD
vs. SUPPLY VOLTAGE
MAX4896 toc09
SUPPLY VOLTAGE (V)
INPUT LOGIC THRESHOLD (V)
5.14.73.1 3.5 3.9 4.3
0.75
1.00
1.25
1.50
1.75
2.00
2.25
2.50
0.50
2.7 5.5
MAX4896 Space-Saving, 8-Channel Relay/Load Driver
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Typical Operating Characteristics
(TA = +25°C, unless otherwise noted.)
TURN-ON/TURN-OFF DELAY TIME
vs. SUPPLY VOLTAGE
MAX4896 toc10
SUPPLY VOLTAGE (V)
t
ON
/t
OFF
DELAY TIME (ms)
3.53.43.33.23.13.02.92.8
0.5
1.0
1.5
2.0
2.5
3.0
0
2.7 3.6
VOUT = 15V RL = 300Ω
CL = 50pF
tOFF
tON
OUT CLAMP VOLTAGE
vs. TEMPERATURE
MAX4896 toc13
TEMPERATURE (°C)
0UT CLAMP VOLTAGE (V)
1109565 80-10 5 20 35 50-25
64.2
64.4
64.6
64.8
65.0
65.2
65.4
65.6
65.8
66.0
64.0
-40 125
TURN-ON/TURN-OFF DELAY TIME
vs. SUPPLY VOLTAGE
MAX4896 toc11
SUPPLY VOLTAGE (V)
tON/tOFF DELAY TIME (µs)
5.35.14.94.7
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0
4.5 5.5
tOFF
tON
RL = 150Ω
CL = 50pF
VOUT = 50V
BACK-EMF CLAMPING
WITH STANDARD +12V RELAY
MAX4896 toc14
RESET
(2V/div)
OUT
(20V/div)
1ms/div
VS = 3.3V
OUTPUT CURRENT LIMIT (mA)
450
500
550
600
700
650
750
800
400
OUT_ CURRENT LIMIT
vs. SUPPLY VOLATGE
MAX4896 toc12
SUPPLY VOLTAGE (V)
5.35.14.94.74.5 5.5
TA = -40°C
TA = +125°C
TA = +85°C
TA = +25°C
MAX4896 toc15
OUT
(20V/div)
BACK-EMF CLAMPING
WITH STANDARD +24V RELAY
1ms/div
VS = 5V
RESET
5V/div
MAX4896 Space-Saving, 8-Channel Relay/Load Driver
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Typical Operating Characteristics (continued)
PIN NAME FUNCTION
1RESET Reset Input. Drive RESET low to clear all latches and registers (all outputs are turned off). All OUT
pulldown currents are disabled when RESET = low.
2CS Chip Select Input. Drive CS low to select the device. When CS is low, data at DIN is clocked into the
8-bit shift register on SCLK’s rising edge. Drive CS from low to high to latch the data to the registers.
3DIN Serial Data Input
4SCLK Serial Clock Input
5DOUT Serial Data Output. DOUT is the output of the 8-bit shift register. This output can be used to daisy chain
multiple MAX4896s. The data at DOUT appears synchronous to SCLK’s falling edge.
6PDCD Pulldown Current Disable. Drive PDCD high to disable OUT’s pulldown current source. Drive PDCD low
to enable OUT_ pulldown current source. PDCD must be low to detect an open-load fault.
7 SPLD
Short-Protection Latch-Off Disable Input. Drive SPLD high to disable the built-in short-circuit protection
latch-off feature. When SPLD is low, an overloaded channel is turned off immediately. See the Output
Short-Circuit/Current-Limiting Protection section.
8OUT8 Open-Drain Output 8. Connect OUT8 to the low side of a relay coil. OUT8 is pulled to PGND when
activated and is otherwise high impedance.
9OUT9 Open-Drain Output 7. Connect OUT7 to the low side of a relay coil. OUT7 is pulled to PGND when
activated and is otherwise high impedance.
10, 16 PGND Power Ground. PGND is the ground return path for the output sinks. Connect PGND pins together and
to GND.
11 OUT6 Open-Drain Output 6. Connect OUT6 to the low side of a relay coil. OUT6 is pulled to PGND when
activated and is otherwise high impedance.
12 OUT5 Open-Drain Output 5. Connect OUT5 to the low side of a relay coil. OUT5 is pulled to PGND when
activated and is otherwise high impedance.
13 GND Ground
14 OUT4 Open-Drain Output 4. Connect OUT4 to the low side of a relay coil. OUT4 is pulled to PGND when
activated and is otherwise high impedance.
15 OUT3 Open-Drain Output 3. Connect OUT3 to the low side of a relay coil. OUT3 is pulled to PGND when
activated and is otherwise high impedance.
17 OUT2 Open-Drain Output 2. Connect OUT2 to the low side of a relay coil. OUT2 is pulled to PGND when
activated and is otherwise high impedance.
18 OUT1 Open-Drain Output 1. Connect OUT1 to the low side of a relay coil. OUT1 is pulled to PGND when
activated and is otherwise high impedance.
19 VSInput Supply Voltage. Bypass VS to GND with a 0.1μF capacitor.
20 FLAG Open-Drain Fault Output. FLAG asserts low when a fault occurs at OUT1–OUT8.
—EP Exposed Paddle. Internally connected to GND. Connect to a large PCB ground plane to improve
thermal dissipation. Enhances thermal conductivity; not intended as an electrical connection point.
MAX4896 Space-Saving, 8-Channel Relay/Load Driver
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Pin Description
Detail Description
The MAX4896 is an 8-channel relay and load driver for
medium voltage applications up to 50V. The MAX4896
features built-in inductive kickback protection, drive for
latching/nonlatching, or dual-coil relays and an internal
register for detecting open-load and short-circuit faults.
Each independent open-drain output features a 3Ω onre-
sistance and is guaranteed to sink 400mA at VS ≥ 4.5V,
and 100mA at VS ≤ 3.6V.
The MAX4896 also incorporates a logic input (PDCD)
that allows the device to continue operating when an
overcurrent condition lasts longer than the 280μs (max)
fault delay time. A built-in overvoltage protection clamp
handles kickback voltage transients, which are common
when driving inductive loads. Thermal-shutdown circuitry
shuts off all outputs (OUT_) when the junction tempera-
ture exceeds +160°C.
The MAX4896 employs a reset input that allows the user to
turn off all outputs simultaneously with a single control line.
The MAX4896 includes a 10MHz SPI-/QSPI-/MICROWIRE
compatible serial interface. The serial interface is compat-
ible with TTL-/CMOS-logic voltage levels and operates
with a single +2.7V to +5.5V supply.
Serial Interface
The serial interface consists of an 8-bit input shift regis-
ter, a parallel latch (output control register) controlled by
SCLK and CS, and an output status register containing
diagnostics information. The input to the shift register
is an 8-bit word. Each data bit controls one of the eight
outputs, with the most significant bit (D7) corresponding
to OUT8, and the least significant bit (D0) corresponding
to OUT1 (see Table 1). When CS is low, data at DIN is
clocked into the shift register synchronously with SCLK’s
rising edge. Driving CS from low to high latches the data
in the shift register to the output control register.
DOUT is the output of the internal output status register
for diagnostics purposes (see Figure 2 and Tables 2 and
3). Status data for each channel is transferred to the shift
register at the falling edge of CS. The data bits contained
in the shift register are then transferred to the DOUT out-
put synchronously with SCLK’s falling edge.
While CS is low, the switches always remain in their previ-
ous states. Drive CS high after 8 bits of data have been
shifted in to update the output state, and to further inhibit
data from entering the shift register. When CS is high,
transitions at DIN and SCLK have no effect on the output,
and the first input bit (D7) is present at DOUT.
If the number of data bits entered while CS is low is
greater or less than 8, the shift register contains only the
last 8 data bits, regardless of when they were entered.
The 3-wire serial interface is compatible with SPI, QSPI,
and MICROWIRE standards. The latch that drives the
analog output stages is updated on the rising edge of CS,
regardless of SCLK’s state.
Diagnostic Information
The MAX4896 contains an internal output status register
used for diagnostics information for each output (see
Tables 1, 2, and 3). When a fault condition is detected
at any channel for longer than the minimum fault-filtering
time (tD(FAULT)_min), the fault information is latched into
the corresponding position in the output status register
(see Table 2), and the FLAG asserts. Status/diagnostics
data for each channel in the output status register is trans-
ferred to the output shift register at the falling edge of CS.
While CS is low, the diagnostics bits are then transferred
to DOUT synchronously with SCLK’s falling edge. A rising
edge at CS resets the output status register data. During
normal operation,the output status bit is the same as the
DIN bit (DO1 = D1, DO2 = D2). When the MAX4896 is
operating with a fault condition, the output status bit is the
inverse of the DIN bit (DO1 = 0, D1 = 1).
Figure 1. Serial Interface
8-BIT SHIFT REGISTER
OUTPUT CONTROL REGISTER (OUT)
DOUT
OUTPUT STATUS REGISTER (OSR)
LATCHED ON CS:
LATCHED ON CS:
DIN
SCLK
CS
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Table 1. Serial-Input Address
Table 2. Serial-Output Address
Table 3. Status-Register Output Diagnostic
Figure 2. 3-Wire Serial-Interface Timing
DIN D0 D1 D2 D3 D4 D5 D6 D7
OUT_ OUT1 OUT2 OUT3 OUT4 OUT5 OUT6 OUT7 OUT8
DIN DO0 DO1 DO2 DO3 DO4 DO5 DO6 DO7
OUT_ OUT1 OUT2 OUT3 OUT4 OUT5 OUT6 OUT7 OUT8
OUTPUT STATUS DO_STATUS BIT DIAGNOSTIC
Off Low Normal operation.
Off High Fault condition. Output open or short circuit.
On Low Fault condition. Short circuit to positive load voltage.
On High Normal operation.
SCLK
DIN
DOUT
tCSS tCL tCH
tCSW
tCSH
tDO
tON,
tOFF
tCSO
tDS
tDH
D7 D6 D1 D0
CS
OUT_
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The minimum fault-filtering time helps mask short-duration
fault conditions, such as driving highly capacitive loads.
The typical diagnostics software routine works as follows:
● Write data to the MAX4896
● Wait for tD(FAULT) maximum to ensure diagnostics
data is ready and valid
● Write same data to the MAX4896 and read out the
diagnostics data from the shift register
Use Table 3 to diagnose the output state.
To reduce processor overhead, an interrupt-based diag-
nostics routine is possible. The diagnostics routine will
analyze diagnostics data only when the FLAG output trig-
gers an interrupt.
Output Short-Circuit/
Current-Limiting Protection
The MAX4896 channels (OUT_) are protected against
short-circuits conditions. When the channel’s output cur-
rent exceeds the current-limit threshold (ILIM) for longer
than the minimum fault-filtering time (tD(FAULT) min), the
short-circuit protection is activated. The shortcircuit pro-
tection behavior is determined by the logic level at SPLD.
When SPLD = high, an overloaded channel remains in
a current-limited state until the short-circuit condition is
removed or thermal shutdown is reached. This allows the
operation of loads where the inrush currents may exceed
the MAX4896 internal current limit.
When SPLD = low, an overloaded channel immediately
turns off (latched-off). When a shorted output is latched
off, the channel can be turned back on after the next serial
input data is latched into the MAX4896.
Open-Load Detection
The MAX4896 features an output pulldown current source,
along with a voltage comparator, to detect an open-load
fault condition. To enable the open-load detection func-
tion, PDCD must be low. The voltage at OUT_ is com-
pared with the diagnostics threshold voltage (VDS(OL))
to determine whether a open-load fault condition exists.
Thermal Shutdown
If the junction temperature exceeds +160°C, all outputs
are switched off immediately (no filtering time) and FLAG
asserts. The hysteresis is approximately +20°C, disabling
thermal shutdown once the temperature drops below
+140°C.
RESET
The MAX4896 features an asynchronous reset input that
allows the user to simultaneously turn all outputs off using
a single control line. Drive RESET low to clear all latches
and registers, and to turn off all outputs. While RESET is
low, the OUT pulldown currents are disabled, regardless
of the state of PDCD.
FLAG Output
FLAG is an open-drain latched output that can be con-
nected to a μP interrupt and pulls low whenever a fault
condition (short-circuit and/or open-load) is detected in
any of the eight outputs for longer than the minimum
fault-filtering time (tD(FAULT) min). When not using all
channels, connect unused outputs to VS through a 10kΩ
pullup resistor to avoid inadvertently triggering the FLAG.
FLAG asserts immediately, (no filtering time), when a
thermal-shutdown fault condition is detected. The latch
FLAG deasserts on CS rising edge.
Applications Information
Daisy Chaining
The MAX4896 features a digital output (DOUT) that
provides a simple way to daisy chain multiple devices.
This feature allows the user to drive large banks of relays
using only a single serial interface. To daisy chain multiple
devices, connect all CS inputs together and connect the
DOUT of one device to the DIN of another device (see
Figure 3). During operation, a stream of serial data is
shifted through all the MAX4896s in series.
Inductive Kickback Protection
Each output features an output protection clamp, limiting
the OUT voltage to 65V (typ). The clamp protects against
voltage transient when driving inductive loads.
MAX4896 Space-Saving, 8-Channel Relay/Load Driver
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Figure 3. Daisy-Chain Configuration
MAX4896 MAX4896
DOUTDIN
OUT1
OUT8
PGND PGND
GND
CS
SCLK
VS
VS
0.1µF
VS
VS
0.1µF
CS
SCLK
DIN
DEVICE 1 DEVICE 2
DOUTDIN
OUT1
OUT8
GND
CS
SCLK
SPI/CONTROL
INTERFACE
8-BIT
LATCH
CHANNEL 1
CHANNEL 2
CHANNEL 3
CHANNEL 4
CHANNEL 5
CHANNEL 6
CHANNEL 7
CHANNEL 8
GATE CONTROL
AND CURRENT
LIMITING
OPEN / SHORT
DETECT
CLAMP
OVERTEMPERATURE
PROTECTION
DIN
DOUT
SCLK
FLAG
CS
OUT1
OUT2
OUT3
OUT4
OUT5
OUT6
OUT7
OUT8
PGNDGND
RESET
SPLDPDCDVS
MAX4896
MAX4896 Space-Saving, 8-Channel Relay/Load Driver
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Functional Diagram
PACKAGE
TYPE
PACKAGE
CODE
OUTLINE
NO.
LAND
PATTERN NO.
20 TQFN-EP T2055+5 21-0140 90-0010
19
20
18
17
7
6
8
CS
SCLK
DOUT
9
RESET
OUT4
OUT5
OUT6
OUT3
1 2
OUT1
OUT2
4 5
15 14 12 11
VS
FLAG
OUT7
OUT8
SPLD
PDCD
MAX4896
DIN GND
3
13
16 10 PGND
PGND
*EP
TQFN
(5mm x 5mm)
+
TOP VIEW
*EXPOSED PAD. CONNECT TO PGND.
MAX4896 Space-Saving, 8-Channel Relay/Load Driver
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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.
Chip Information
PROCESS: BiCMOS
Pin Conguration
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
010/05 Initial release —
1 6/07 Removal of future product notice -
212/07 EP clarication 7
37/12 Updated FLAG Output section 10
45/14 Removed automotive reference under Applications section 1
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 specications 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.
MAX4896 Space-Saving, 8-Channel Relay/Load Driver
© 2014 Maxim Integrated Products, Inc.
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13
Revision History
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.
