Pololu High-Power Motor Driver 36v9Pololu
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 absolute maximum voltage for this motor driver is 50 V. 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 9 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 about 12 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.
High-Power Motor Driver Versions:
There are currently nine versions of the high-power motor driver. The three CS versions have the same pinout, and the six non-CS versions have the same pinout. The following table provides a comparison of the high-power motor drivers:
- Size: 1.3" x 0.8"
- Weight: 2.8 g1
- Motor channels: 1
- Minimum operating voltage: 5.5 V
- Maximum operating voltage: 50 V
- Continuous output current per channel: 9 A2
- Maximum PWM frequency: 40 kHz3
- Maximum logic voltage: 5.5 V
- MOSFET on-resistance (max per leg): 10 mΩ
- Reverse voltage protection?: N
- 1. Without any connectors or through-hole capacitors.
- 2. Typical results with 100% duty cycle at room temperature. Continuous current can be as high as 12 A if the MOSFETs are kept cool with air flow or a heat sink.
- 3. Higher frequencies are possible, but duty cycle will be limited by dead time of approximately 3 μs per cycle.