EVALUATION KIT AVAILABLE
MAX14874
4.5V to 36V Dual Relay/Valve/Motor Driver
General Description
Benefits and Features
The MAX14874 dual push-pull driver provides a small
and simple solution for driving and controlling relays and
valves with voltages between 4.5V and 36V.
●● Drive More Power and Reduce Footprint
• Up to 2.5A Peak Motor Current
• Flexible 4.5V–36V Supply Enables Longer Runtime
The MAX14874 is also designed to drive brushed DC
motors. Separate COM pins allow monitoring of individual
driver load currents. Peak currents up to 2.5A ensure for
PWM controlled large motor torque. Low driver on-resistance
reduces power dissipation.
• Small 3mm x 3mm TDFN-EP Package
●● Low Power Dissipation Runs Cooler and Longer
• 480mΩ (typ) Bridge On-Resistance
●● Simplified Designs Reduces Time to Market
• Individual Current Sensing to Sense Voltages up
to 1V
• Charge-Pump-Less Architecture
• Independent Driver Control for Each Driver
●● Integrated Protection Provides Robust Driving Solutions
• Thermal Shutdown Undervoltage Lockout
• Diagnostic FAULT Output
• -40°C to +85°C Temperature Range
The MAX14874 features a charge-pump-less design for
reduced external components and low supply current.
The MAX14874 features shoot-through protection and
internal free-wheeling diodes that absorb inductive
currents. Driver outputs are short-circuit protected against
shorts to the supply, and between M1 and M2. An
active-low FAULT output signals thermal overload and
overcurrents during fault conditions.
The MAX14874 is available in a 12-pin TDFN-EP (3mm
x 3mm) package and operates over the -40°C to +85°C
temperature range.
Applications
●● Valve and Relay Control
●● Motor Control
●● Coffee Machines
Ordering Information appears at end of data sheet.
Functional Diagram
VDD
M1
VDD
M2
VDD
EN1
EN2
DRIVER
DRIVER
IN1
IN2
FAULT
FAULT
DETECTION
GND
19-100010; Rev 0; 4/17
MAX14874
COM1
COM2
MAX14874
4.5V to 36V Dual Relay/Valve/Motor Driver
Absolute Maximum Ratings
(All voltages referenced to GND)
VDD.........................................................................-0.3V to +40V
M1, M2........................................................ -0.3V to (VDD+0.3V)
IN1, IN2, EN1, EN2, FAULT.............................................. -0.3V to +6.0V
COM1, COM2........................................................-0.3V to +1.2V
Current Into M1, M2 ..............................................................±3A
Continuous Power Dissipation (TA = +70°C)
Multiple-Layer Board (derate at 24.4mW/°C
above +70°C).............................................................1951mW
Operating Temperature Range............................ -40°C to +85°C
Junction Temperature....................................................... +150ºC
Storage Temperature Range..............................-65ºC to +150°C
Lead Temperature (Soldering, 10s) ................................. +300°C
Solder Temperature (Reflow) ..........................................+260°C
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 (Note 1)
Junction-to-Case Thermal Resistance (θJC)
TDFN-EP (Single-Layer Board)...................................8.5°C/W
TDFN-EP (Multiple-Layer Board)................................8.5°C/W
Junction-to-Ambient Thermal Resistance (θJA)
TDFN-EP (Single-Layer Board)....................................63°C/W
TDFN-EP (Multiple-Layer Board).................................41°C/W
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.
Electrical Characteristics
(VDD = 4.5V to 36V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VDD = 12V, TA = +25°C)(Note 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
36
V
POWER SUPPLY
Supply Voltage
Supply Current
VDD
IDD
Undervoltage Lockout
Threshold
VUVLO
Undervoltage Lockout
Threshold Hysteresis
VUVLO_HYST
4.5
EN1 = EN2 = high,
M1/M2 not connected
switching at
50kHz
1
No switching
0.5
1.2
3.8
4.3
VDD rising
3.3
mA
400
V
mV
DRIVER (M1, M2)
Driver Output Resistance
(High-Side + Low-Side)
Driver Overload Current Limit
RON
IM_LKG
COM1, COM2 Voltage Range
VCOM
COM1, COM2 On Leakage
Current
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TJ = 25°C
280
395
TJ = 125°C
410
580
IM_OL
M1, M2 Leakage Current
COM1, COM2 Off Leakage
Current
COM1 = COM2 =
GND, IM_ = 2.5A
ICOM_LKG_
OFF
ICOM_LKG_ON
3
EN_ = low VM_ = 0V or VDD
mΩ
A
-1
+1
μA
-0.25
+1
V
EN_ = low, VCOM_ = 0V or 1V, M_
unconnected
-3
0
μA
EN_ = high, IN_ = high or low, VCOM_
= 0V or 1V, M_ unconnected
-3
0
μA
Maxim Integrated │ 2
MAX14874
4.5V to 36V Dual Relay/Valve/Motor Driver
Electrical Characteristics (continued)
(VDD = 4.5V to 36V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VDD = 12V, TA = +25°C)(Note 2)
PARAMETER
M1, M2 Body Diode ForwardVoltage
SYMBOL
VBF
LOGIC SIGNALS (IN1, IN2, EN1, EN2, FAULT)
CONDITIONS
MIN
TYP
MAX
Low-side diode, EN_ = low, IF = 2.5A
1.5
High-side diode, EN_ = low, IF = 2.5A
1.5
Input Logic-High Voltage
VIH
IN1, IN2, EN1, EN2
Input Logic-Low Voltage
VIL
IN1, IN2, EN1, EN2
Input Leakage Current
IIL
IN1, IN2, EN1, EN2, VINPUT = 5.5V or
0V
FAULT Output Low Voltage
VOL
FAULT Off Leakage Current
IF_LKG
FAULT deasserted, VFAULT = 5.5V
Thermal-Shutdown Threshold
TSHDN
Temperature rising, FAULT asserted
Thermal-Shutdown Hysteresis
TSHDN_HYST
2
UNITS
V
V
-1
FAULT asserted, ISINK = 5mA
-1
0.8
V
+1
μA
0.5
V
+1
μA
PROTECTION
+160
°C
10
°C
AC Electrical Characteristics
(VDD = 4.5V to 36V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VDD = 12V, TA = +25°C)(Note 2)
PARAMETER
Switching Frequency
Dead Time
SYMBOL
CONDITIONS
fSW
EN_ = high, Switching signal applied
at IN_
MIN
TYP
MAX
UNITS
50
kHz
tDEAD
140
ns
M1, M2 Slew Rate
SR
200
V/μs
M1, M2 High-Side Propagation
Delay
tPR
RL = 1kΩ, CL = 50pF, IN_ rising,
Figure 1
620
ns
M1, M2 Low-Side Propagation
Delay
tPF
RL = 1kΩ, CL = 50pF, IN_ falling,
Figure 1
583
ns
Overcurrent Blanking Time
tOC_BL
M1/M2 is shorted to VDD or GND,
Figure 2
1
μs
Overcurrent Autoretry Timeout
tOC_TO
IN_ = high, EN_ = high, IM_ > IM_OL,
Figure 2
2
ms
Enable Turn-on Delay
tEN_ON
IN_ = high, RL = 1kΩ, CL = 50pF,
EN_ rising, M_ rising to 10%, Figure
3
1
μs
Enable Turn-off Delay
tEN_OFF
IN_ = high, RL = 1kΩ, CL = 50pF,
EN_ falling, M_ falling to 90%, Figure
3
1
μs
Note 2: All units are production tested at TA = +25°C. Specifications over temperature are guaranteed by design.
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Maxim Integrated │ 3
MAX14874
4.5V to 36V Dual Relay/Valve/Motor Driver
Test Circuits/Timing Diagrams
M1 or M2
RL
CL
HIGH
IN1 or IN2
LOW
1V
VDD
M1 or M2
1V
tPR
0V
tPF
Figure 1. M1/M2 Propagation Delays
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Maxim Integrated │ 4
MAX14874
4.5V to 36V Dual Relay/Valve/Motor Driver
Test Circuits/Timing Diagrams (continued)
IM1 or IM2
IM_OL
0A
tOC_BL
VL
FAULT
0V
tOC_TO
Figure 2. Overcurrent Autoretry Timeout
M1 or M2
RL
CL
HIGH
EN1 or EN2
LOW
VDD
90%
M1 or M2
10%
tEN_ON
0V
tEN_OFF
Figure 3. Enable/Disable Delays
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Maxim Integrated │ 5
MAX14874
4.5V to 36V Dual Relay/Valve/Motor Driver
Typical Operating Characteristics
(VDD = 24V, TA = +25°C, unless otherwise noted.)
HIGH-SIDE ON RESISTANCE
vs. LOAD CURRENT
0.30
toc01
LOW-SIDE ON RESISTANCE
vs. LOAD CURRENT
0.20
toc02
0.18
ON-RESISTANCE (Ω)
ON-RESISTANCE (Ω)
0.20
0.15
VDD = 36V
0.10
VDD = 4.5V
0.30
0.14
0.12
VDD = 36V
0.10
0.08
0.06
0.04
0.05
0.00
0
1000
2000
0
3000
0.20
0.15
0.10
LOW-SIDE
1000
2000
3000
0.00
-45
LOAD CURRENT (mA)
LOAD CURRENT (mA)
toc04
1.6
1.4
HIGH-SIDE
0.25
0.05
0.02
0.00
-20
5
30
55
80
105
130
TEMPERATURE (oC)
toc05
1.2
VDD = 36V
toc03
ILOAD = 1A
0.35
0.16
VDD = 4.5V
ON-RESISTANCE (Ω)
0.25
ON-RESISTANCE
vs. TEMPERATURE
0.40
toc06
1.2
1.0
1.0
0.8
0.8
0.8
0.6
0.6
TA = -40°C
TA = 25°C
VBF (V)
VDD = 24V
1.0
VBF (V)
ICC (mA)
1.2
TA = 85°C
TA = 25°C
0.6
TA = 85°C
TA = -40°C
0.4
0.4
0.2
0.2
VDD = 12V
0.4
VDD = 5V
0.2
CL = 10pF on M1/M2
0.0
0
5
10
15
20
0.0
25
30
DATA RATE (kHz)
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35
40
45
50
0.0
0
1
2
LOAD CURRENT (A)
3
0
1
2
3
LOAD CURRENT (A)
Maxim Integrated │ 6
MAX14874
4.5V to 36V Dual Relay/Valve/Motor Driver
M2
VDD
GND
EN2
FAULT
TOP VIEW
COM2
Pin Configuration
12
11
10
9
8
7
MAX14874
1
2
3
4
5
6
COM1
M1
VDD
EN1
IN1
IN2
+
TDFN-EP
3mm x 3mm
Pin Description
PIN
NAME
1
COM1
2
M1
Driver Output 1. See the Function Table for more information.
3, 10
VDD
Power Supply Input. Bypass VDD to GND with a 1μF ceramic capacitor as close to the device as
possible. Connect both VDD pins together.
4
EN1
Active-High Enable Input 1. Drive EN1 high to enable the M1 driver output. M1 is high impedance when EN1 is low.
5
IN1
Control Logic Input 1. Pull IN1 high to drive M1 high. Pull IN1 low to drive M1 low. See the Function Table
for more information.
6
IN2
Control Logic Input 2. Pull IN2 high to drive M2 high. Pull IN2 low to drive M2 low. See the Function Table
for more information.
7
FAULT
Open-Drain Active-Low Fault Output. FAULT goes low during a short circuit or overcurrent condition and
thermal shutdown.
8
EN2
Active-High Enable Input 2. Drive EN2 high to enable the M2 driver output. M2 is high impedance when
EN2 is low.
9
GND
Ground
11
M2
12
COM2
—
EP
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FUNCTION
COM1 Current Output. Connect COM1 to GND or connect a sense resistor, RSENSE1, from COM1 to
GND to monitor the current flowing into/out of COM1.
Driver Output 2. See the Function Table for more information.
COM2 Current Output. Connect COM2 to GND or connect a sense resistor, RSENSE2, from COM1 to
GND to monitor the current flowing into/out of COM2.
Exposed Pad. Connect to ground.
Maxim Integrated │ 7
MAX14874
4.5V to 36V Dual Relay/Valve/Motor Driver
Function Table
EN_/IN_Control Logic
INPUTS
M_ OUTPUT
EN_
IN_
0
X
High-Impedance
1
0
GND
1
1
VDD
X = Don’t care
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Maxim Integrated │ 8
MAX14874
4.5V to 36V Dual Relay/Valve/Motor Driver
Functional Diagram
24V
3.3V
IRQ
*
*
3.3V
24V
VDD
FAULT
M1
24V
VDD
M2
DRIVER 2
IN2
MCU
DRIVER 1
IN1
MAX14874
EN1
EN2
COM2
COM1
ADC
GND
RSENSE1
A
* OPTIONAL DIODE. SEE THE SHORT-CIRCUIT PROTECTION SECTION FOR MORE INFORMATION.
Detailed Description
The MAX14874 relay/valve driver, which can also be used
as a DC brushed motor driver, provides a low-power and
flexible solution for driving and controlling loads with voltages between 4.5V and 36V. Peak currents of up to 2.8A
ensure for large force/torque that is controllable by an
external PWM signal.
Charge-pump-less design ensures for minimal external
components and low supply current.
Shoot-through protection with a 140ns (typ) dead time
ensures low operating current. Internal free-wheeling
diodes absorb inductive motor currents. The FAULT output
signals thermal overload and overcurrents.
Overcurrent Protection
The MAX14874 is protected against shorts on M1/M2 to
VDD and between M1 and M2 via overcurrent limiting.
When a current above 6A (typ) flows through M1 or M2
for longer than 1µs, an overcurrent condition is detected
and the H-bridge drivers are automatically disabled and
the FAULT output asserts.
If the overcurrent condition continues for longer than the
overcurrent autoretry timeout (2ms, typ) the MAX14874
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enters autoretry mode. In autoretry mode, the M1 and M2
outputs are re-enabled for 1µs (typ) and FAULT goes high
impedance. The drivers are disabled again and FAULT is
re-asserted if the overcurrent condition persists.
Short Circuit Protection
The M1 and M2 outputs are safe against all short circuits,
if the RSENSE_ resistors on COM1 and/or COM2 have a
value of less than 50mΩ.
When using a larger sense resistor, protect the part
against shorts to GND by connecting a silicon diode (for
example MURA205T3) between the M_ driver output
and ground. These protection diodes are not needed
if the maximum operating supply voltage (VDD) is less
than 24V, and the sense resistor, RSENSE_, on COM_ is
100mΩ or less.
Driver Control
The IN_ input is used for motor speed/torque control.
Increasing or decreasing the duty cycle at IN_ sets the
effective (average) voltage across the motor terminals
and allows current control.
When IN_ is logic-high, the motor is driven high (see
Function Table). When IN_ is logic low, M_ pin is driven low.
Maxim Integrated │ 9
MAX14874
4.5V to 36V Dual Relay/Valve/Motor Driver
Slope Control
Power Considerations
Thermal Shutdown
PTOTAL = PDRIVER + PSW + PD
The power dissipated inside of the driver is calculated as:
The MAX14874 drivers turn-on and turn-off with active
slope control during the M1/M2 transition times. This
integrated slew rate limiting reduces EMC, like conducted
and radiated EMI, associated with high di/dt and dv/dt
rates.
The MAX14874 driver can generate more internal heat/
power than the package for the device can safely dissipate. Total power dissipation for the device is calculated
using the following equation:
The MAX14874 includes integrated protection against
thermal overload. When the junction temperature exceeds
160°C (typ), the M1 and M2 outputs are tri-stated and
FAULT asserted.
M1 and M2 are automatically re-enabled when the
junction temperature falls to 150°C (typ).
PDRIVER = IM_LOAD2 x RON
where IM_LOAD is the load current and RON is the onresistance of the high and low-side FETs.
PSW is the power generated by the driver during the rise/
fall times in switching, and includes both arms of the bridge.
Calculate PSW using the following equation:
Current Sensing with RSENSE
PSW = IM_LOAD x 2 x VDS
= IM_LOAD x 2 x (1/2 x VDD x fSW x tR)
where IM_LOAD is the load current, tR is the 200ns
(typ) rise or fall time of the driver output, and fSW is the
switching frequency.
The internal diodes dissipate power during switching, as
well. Calculate the power dissipated in the diodes as:
Connect a sense resistor (RSENSE_) between COM_ and
GND to monitor the load current through that driver during
operation. Select RSENSE such that the voltage at COM_
does not exceed 1V.
Applications Information
Layout Considerations
Connect VDD pins together with low-resistance traces.
Place a bypass capacitor next to each VDD pin, as close
to the device as possible.
PD = IM_LOAD x 2 x VBF x tDEAD x fSW
20V
M
*
*
3.3V
VDD
M1
M2
3.3V
VDD
VDD
MAX14874
FAULT
IRQ
IN1
µC PWM1
IN2
PWM2
DRIVER
DRIVER
EN1
EN2
ADC
COM1
A
GND
COM2
RSENSE
* OPTIONAL DIODE. SEE THE SHORT-CIRCUIT PROTECTION SECTION FOR MORE INFORMATION.
Figure 4. Motor Control Operation with External Current Regulation
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Maxim Integrated │ 10
MAX14874
4.5V to 36V Dual Relay/Valve/Motor Driver
Chip Information
Ordering Information
PART
MAX14874ETC+
TEMP RANGE
PIN-PACKAGE
-40°C to +85°C
12 TDFN-EP
PROCESS: BiCMOS
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad
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.
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PACKAGE
TYPE
PACKAGE
CODE
OUTLINE
NO.
LAND
PATTERN NO.
12 TDFN-EP
TD1233-1
21-0664
90-0397
Maxim Integrated │ 11
MAX14874
4.5V to 36V Dual Relay/Valve/Motor Driver
Revision History
REVISION
NUMBER
REVISION
DATE
0
4/17
DESCRIPTION
Initial release
PAGES
CHANGED
—
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.
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