Datasheet

board has an absolute maximum voltage rating of 50 V; higher voltages can permanently destroy the
motor driver. Under normal operating conditions, ripple voltage on the supply line can raise the
maximum voltage to more than the average or intended voltage, so a safe maximum voltage is
approximately 44 V.
Note: Battery voltages can be much higher than nominal voltages when they are charged, so the
maximum battery voltage we recommend is 36 V unless appropriate measures are taken to limit the
peak voltage.
The versatility of this driver makes it suitable for a large range of currents and voltages: it can deliver
up to 20 A of continuous current with a board size of only 1.8" by 1.2" and no required heat sink. With
the addition of a heat sink, it can drive a motor with up to about 32 A of continuous current. The
module offers a simple interface that requires as few as two I/O lines while allowing for both sign-
magnitude and locked-antiphase operation, and an optional third control input unique to this board
allows for coasting. This board also features a current-sensing circuit that measures bidirectional motor
current with a magnitude up to 30 A and outputs an analog voltage.
Integrated detection of various short-circuit conditions protects against common causes of catastrophic
failure; however, please note that the board does not include reverse power protection or any over-
current or over-temperature protection. We recommend you use the integrated current sensor to keep
the driver from delivering more current than it can safely handle.
Using the Motor Driver
Connections
The motor and motor power connections are on one side of the board, and the control connections (5V
logic) are on the other side. The motor supply should be capable of delivering the high current the
motor will require, and a large capacitor should be installed between V+ and ground close to the motor
driver to decrease electrical noise. Two axial capacitors are included and one or both can be installed by
soldering them into the V+ and GND pins (labeled '+' and '-' on the bottom silkscreen) along the long
edges of the board. Such installations are compact but might limit heat sinking options; also, depending
on the power supply quality and motor characteristics, a larger capacitor might be required. There are
two options for connecting to the high-power signals (V+, OUTA, OUTB, GND): large holes on 0.2"
centers, which are compatible with the included terminal blocks, and pairs of 0.1"-spaced holes that can
be used with perfboards, breadboards, and 0.1" connectors.
Warning: Take proper safety precautions when using high-power electronics. Make sure you know
what you are doing when using high voltages or currents! During normal operation, this product can
get hotenough to burn you. Take care when handling this product or other components connected to it.
The logic connections are designed to interface with 5V systems (5.5 V max); the minimum high input
signal threshold is 3.5 V, so we do not recommend connecting this device directly to a 3.3 V controller.
In a typical configuration, only PWMH and DIR are required, but PWML can be used to enable
coasting if both PWML and PWMH are driven low. PWML is pulled high and PWMH is pulled low
internally. The two fault flag pins (FF1 and FF2) can be monitored to detect problems (see the Fault
Flag Table below for more details). The RESET pin, when held low, puts the driver into a low-power
sleep mode and clears any latched fault flags. The V+ pin on the logic side of the board gives you