EVALUATION KIT AVAILABLE
MAX14871
4.5V to 36V Full-Bridge DC Motor Driver
General Description
The MAX14871 DC motor driver provides a low-power
and simple solution for driving and controlling brushed
motors with voltages between 4.5V and 36V. Very low
driver on resistance reduces power during dissipation.
The MAX14871 features a charge-pump-less design for
reduced external components and low supply current.
Integrated current regulation allows user-defined peak startup
motor currents and requires minimal external components.
The MAX14871 includes 3 modes of current regulation:
fast decay, slow decay, and 25% current ripple modes.
Current regulation based on 25% ripple simplifies the
design and enables regulation independent of motor
characteristics. A separate voltage sense input (SNS) reduc-
es current-sensing errors due to parasitic trace resistance.
The MAX14871 features shoot-through protection and
internal free-wheeling diodes that absorb inductive motor
currents. Driver outputs are short-circuit-protected from
shorts to ground, to the supply, and between M1 and M2.
An active-low
FAULT
output signals thermal overload and
overcurrents during fault conditions.
The MAX14871 is available in a 16-pin TSSOP-EP package
and operates over the -40°C to +85°C temperature range.
Benefits and Features
●
Drive More Power and Reduce Footprint
• Up to 2.8A Peak Motor-Current Package
• Flexible 4.5V–36V Supply Enables Longer Runtime
●
Low Power Consumption Runs Cooler and Longer
•
334mΩ
(typ) Total Bridge On-Resistance
• 1mA (typ) Supply Current at 30kHz/24V
• 10µA (max) Standby Current at 12V
●
Simplified Designs Reduces Time to Market
• Charge-Pump-Less Architecture
• Current Regulation Only Requires a Sense Resistor
•
Current-Sense Input Simplifies PCB Layout
• Internal/External V
REF
for Current Regulation
• Fast/Slow/25% Ripple Current Regulation Modes
●
Integrated Protection Provides Robust Driving Solutions
• Short-Circuit-Protected Drivers
• Thermal Shutdown Undervoltage Lockout
• Diagnostic FAULT Output
• -40°C to +85°C Temperature Range
Applications
Ordering Information
appears at end of data sheet.
●
Printers and Scanners
●
Industrial Automation
●
Vending and Gaming Machines
Typical Application Circuit
24V
M
3.3V
V
DD
3.3V
M1
M2
MAX14871
IRQ
µC
GPO
PWM
FAULT
DIR
PWM
EN
3.3V
DRIVER
DRIVER
V
REF
TCOFF
C
OFF
MODE
CURRENT
REGULATION
V
DD
V
DD
SNS
COM
GND
R
SENSE
19-7063; Rev 0; 9/14
MAX14871
4.5V to 36V Full-Bridge DC Motor Driver
Absolute Maximum Ratings
(All voltages referenced to GND)
V
DD
........................................................................-0.3V to +40V
M1, M2 ....................................................... -0.3V to (V
DD
+0.3V)
PWM, DIR,
FAULT, EN,
SNS, VREF,
MODE, TCOFF
...............................................................
-0.3V to +6.0V
COM .....................................................................-0.3V to +0.3V
Current Into M1, M2 .............................................................±3A
Continuous Power Dissipation (T
A
= +70°C)
Single-Layer Board (derate at 21.3mW/°C
above +70°C) ............................................................1702mW
Multiple-Layer Board (derate at 26.1mW/°C
above +70°C) ............................................................2088mW
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 (θ
JC
)
TSSOP-EP (Single-Layer Board) ..................................3°C/W
TSSOP-EP (Multiple-Layer Board) ................................3°C/W
Junction-to-Ambient Thermal Resistance (θ
JA
)
TSSOP-EP (Single-Layer Board) ................................47°C/W
TSSOP-EP (Multiple-Layer Board) ...........................38.3°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
PARAMETER
POWER SUPPLY
Supply Voltage
Supply Current
(V
DD
= 4.5V to 36V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
DD
= 12V, T
A
= +25°C)(Note 3)
SYMBOL
V
DD
I
DD
I
SHDN
V
UVLO
V
UVLO_HYST
T
J
= 25°C
T
J
= 125°C
3
EN
= High, V
M1
= V
M2
= 0V or V
DD
Low-side diode,
EN
= High, I
F
= 2.8A
High-side diode,
EN
= High, I
F
= 2.8A
-1
+1
1.5
1.5
EN
= low, M1/M2
not connected
EN
= high, Driver
is in shutdown
V
DD
rising
f
PWM
= 50kHz
No switching
V
DD
= 12V
V
DD
= 36V
3.3
CONDITIONS
MIN
4.5
1
0.5
3.7
10
3.8
400
334
465
435
620
1.2
10
20
4.3
TYP
MAX
36
UNITS
V
mA
Shutdown Supply Current
Undervoltage Lockout
Threshold
Undervoltage Lockout
Threshold Hysteresis
DRIVER (M1, M2)
Driver Output Resistance
(High-Side + Low-Side)
Driver Overload Current Limit
M1, M2 Leakage Current
M1, M2 Body Diode Forward-
Voltage
μA
V
mV
R
ON
I
M_OL
I
M_LKG
I
M_
= 2.8A
mΩ
A
μA
V
BF
V
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2
MAX14871
4.5V to 36V Full-Bridge DC Motor Driver
Electrical Characteristics (continued)
(V
DD
= 4.5V to 36V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
DD
= 12V, T
A
= +25°C)(Note 3)
PARAMETER
SYMBOL
CONDITIONS
Fixed Off-Time, Fast Decay Current
Regulation
MODE Select Threshold
V
MODE_TH
25% Ripple Current Regulation
Fixed Off-Time, Slow Decay Current
Regulation
V
MODE
= 5V
0.5
1.5
0.6
0.2
V
DD
≥ 5V
V
DD
< 5V
VREF = 2V
V
SNS
rising, V
VREF
< V
VREF_TH
, All
current regulation modes
0.5
0.5
-1
94
-82
100
-75
V
VREF
/ A
V
0.75 x
V
VREF
/A
V
10
1
2.2
0.4
2
1.3
+1
110
mV
-69
MΩ
V
V
μA
MIN
TYP
MAX
UNITS
CURRENT REGULATION (VREF, SNS, COM, TCOFF, MODE)
0.2
1
V
MODE Internal Pulldown
Resistance
VREF Internal/External Select
Threshold
VREF Voltage Range for Exter-
nal VREF Current Regulation
VREF Input Leakage
SNS Threshold for Internal
V
VREF
Current Regulation
R
MODE_PD
V
VREF_TH
V
VREF
I
VREF_LKG
V
SNS_IVR_
THR
V
falling, 25% Ripple Mode,
V
SNS_IVR_THF SNS
V
VREF
< V
VREF_TH
V
SNS_ER_THR
V
SNS
rising, V
VREF
> V
VREF_TH
,
All current regulation modes
SNS Threshold for External
V
VREF
Current Regulation
Current-Sense Amplifier Gain
SNS Input Leakage Current
COM Leakage Current
TCOFF Current
TCOFF Threshold
V
SNS
falling, 25% Ripple Mode,
V
SNS_ER_THF
V
VREF
> V
VREF_TH
A
V
I
SNS_LKG
I
COM_LKG
I
TCOFF
V
TCOFF
V
IH
V
IL
V
EN_IH
V
EN_IL
I
IL
V
OL
I
F_LKG
T
SHDN
T
SHDN_HYST
PWM, DIR,
EN,
V
INPUT
= 5.5V or 0V
FAULT
asserted, I
SINK
= 5mA
FAULT
deasserted, V
FAULT
= 5.5V
Temperature rising,
FAULT
asserted
-1
-1
PWM, DIR
PWM, DIR
1.6
V
VREF
= 1V (Note 4)
V
SNS
= ±250mV
EN
= High, V
COM
= ±250mV
TCOFF is connected to GND
9.6
-1
-1
6
0.92
2
V
10.5
+1
+1
V/V
μA
μA
μA
V
V
10
1
15
1.08
LOGIC SIGNALS (PWM, DIR,
EN, FAULT)
Input Logic-High Voltage
Input Logic-Low Voltage
EN
Input Logic-High Voltage
EN
Input Logic-Low Voltage
Input Leakage Current
FAULT
Output Low Voltage
FAULT
Off Leakage Current
PROTECTION
Thermal-Shutdown Threshold
Thermal-Shutdown Hysteresis
0.8
0.4
+1
0.5
+1
+160
10
V
V
V
μA
V
μA
°C
°C
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MAX14871
4.5V to 36V Full-Bridge DC Motor Driver
AC Electrical Characteristics
(V
DD
= 4.5V to 36V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
DD
= 12V, T
A
= +25°C)(Note 3)
PARAMETER
PWM Frequency
Dead Time
M1, M2 Slew Rate
M1, M2 High-Side Propagation
Delay
M1, M2 Low-Side Propagation
Delay
Fixed Off-Time with Internal
VREF Current Regulation
Current Regulation Minimum
On-Time
Overcurrent Blanking Time
Overcurrent Autoretry Timeout
Enable Turn-on Delay
SYMBOL
f
SW
t
DEAD
SR
t
PR
t
PF
t
OFF_D
R
L
= 1kΩ, C
L
= 50pF, PWM/DIR ris-
ing, Figure 1
R
L
= 1kΩ, C
L
= 50pF, PWM/DIR fall-
ing, Figure 1
PWM = High,
EN
= Low, V
SNS
>
V
SNS_IVR_THR
, VVREF < VVREF_
TH, TCOFF unconnected
PWM = High,
EN
= Low, V
SNS
>
VSNS_IR_THR or VSNS_ER_THF
M1/M2 is shorted to V
DD
or GND,
Figure 2
PWM = High,
EN
= Low, I
M
or I
M2
>
I
M_OL
, Figure 2
PWM = High, R
L
= 1kΩ, C
L
= 50pF,
EN
falling, M1/M2 rising to 10%,
Figure 3
PWM = High, R
L
= 1kΩ, C
L
= 50pF,
EN
rising, M1/M2 falling to 90%,
Figure 3
7.8
CONDITIONS
EN
= Low, Switching signal applied
at PWM
140
200
620
583
MIN
TYP
MAX
50
UNITS
kHz
ns
V/μs
ns
ns
15
22
μs
t
CR_BL
t
OC_BL
t
OC_TO
t
EN_ON
2.5
1
2
23
μs
μs
ms
μs
Enable Turn-off Delay
t
EN_OFF
50
μs
Note 2:
All units are production tested at T
A
= +25°C. Specifications over temperature are guaranteed by design.
Note 3:
A
V
is the fixed voltage gain of the internal current sense amplifier. It is the factor by which the V
SNS
voltage is multiplied for
comparison with the external VREF voltage when using external VREF current regulation. See the Applications Information
section for more information.
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4
MAX14871
4.5V to 36V Full-Bridge DC Motor Driver
Test Circuits/Timing Diagrams
M1/ M2
R
L
C
L
PWM/DIR
V
L
0V
V
DD
M1/M2
1V
t
PR
t
PF
1V
0V
Figure 1. M1/M2 Propagation Delays
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