The Pololu high-power motor driver is a discrete MOSFET H-bridge designed to drive large DC brushed motors. The H-bridge is made up of one N-channel MOSFET per leg, and most of the board’s performance is determined by these MOSFETs (the rest of the board contains the circuitry to take user inputs and control the MOSFETs). The MOSFET datasheet is available under the “Resources” tab. The 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.