User Manual

PIN Default State Description

VIN

The connection point for the positive side of the 5.5 – 24 V motor

power supply. Since the overvoltage protection can be as low as 24 V,

we do not recommend using 24 V batteries for VIN.

VDD

The connection point for the positive side of the logic power supply

(typically 2.5 – 5 V). The only function of this pin is to power the

internal pull-ups on the enable lines, M1EN/DIAG and M2EN/DIAG.

VOUT

This pin gives you access to the motor power supply after the

reverse-voltage protection MOSFET (see the board schematic in

Section 5). It can be used to supply reverse-protected power to other

components in the system, but it should not be used for high currents.

This pin should only be used as an output.

GND

Ground connection points for logic and motor power supplies. The

controlling device and the motor driver must share a common ground.

MxA/B

Output of half-bridge A/B. Each half-bridge connects to one terminal

of a DC motor.

MxPWM LOW

Pulse-width modulation input: a PWM signal on this pin corresponds

to a PWM output on the corresponding driver’s motor outputs. When

this pin is low, the motor outputs are high impedance. When it is high,

the output state is determined by the states of the MxINA/B and

MxEN/DIAG pins.

MxINA FLOATING Motor direction input A (“clockwise” input).

MxINB FLOATING Motor direction input B (“counterclockwise” input).

MxCS

Current sense output. The pin voltage is roughly 140 mV per amp of

output current when the CS_DIS pin is low or disconnected. The

current sense reading is more accurate at higher currents. (Note that

while the CS voltage can potentially exceed 3.3 V at high currents, the

current sense circuit should be safe for use with many 3.3V analog

inputs. Most MCUs have integrated protection diodes that will clamp

the input voltage to a safe value, and since the CS circuit has a 10 kΩ

resistor in series with the output, only a few hundred microamps at

most will flow through that diode.)

MxEN/

DIAG

HIGH

Combination enable input/diagnostic output. When the driver is

functioning normally, this pin acts as an enable input, with a logical

4. Using as a General-Purpose Motor Driver Page 21 of 35