This discrete MOSFET H-bridge motor driver enables bidirectional control of one high-power DC brushed motor. The little 1.3—0.8-inch board supports a wide 5.5 to 40 V voltage range and is efficient enough to deliver a continuous 12 A without a heat sink, or 18 A with a heat sink.
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 (167k pdf) is available under the Resources¯ tab. The absolute maximum voltage for this motor driver is 40 V, and 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 34 V.
Note: Battery voltages can be much higher than nominal voltages when they are charged, so the maximum nominal battery voltage we recommend is 28 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 12 A of continuous current with a board size of only 1.3" by 0.8" and no required heat sink. With the addition of a heat sink, it can drive a motor with up to 18 A of continuous current. The module offers a simple interface that requires as little as two I/O lines while allowing for both sign-magnitude and locked-antiphase operation. 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.
There are three versions of the high-power motor driver, each with a different operating voltage and current range. The three drivers are the same size and are pin-compatible with one another. Here is a comparison of the motor drivers: