Pololu High-Power Motor Driver 36v20 CSPololu
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.
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:
|Name||Max nominal battery voltage (V)||Max continuous current (A) w/o heat sink|
|High-power motor driver 18v25 CS||18||25|
|High-power motor driver 18v25||18||25|
|High-power motor driver 18v15||18||15|
|High-power motor driver 24v23 CS||28||23|
|High-power motor driver 24v20||28||20|
|High-power motor driver 24v12||28||12|
|High-power motor driver 36v20 CS||36||20|
|High-power motor driver 36v15||36||15|
|High-power motor driver 36v9||36||9|
- Size: 1.8" x 1.2"
- Weight: 7 g1
- Motor channels: 1
- Minimum operating voltage: 5.5 V
- Maximum operating voltage: 50 V
- Continuous output current per channel: 20 A2
- Current sense: 0.066 V/A3
- Maximum PWM frequency: 40 kHz4
- Maximum logic voltage: 5.5 V
- MOSFET on-resistance (max per leg): 4.8 mΩ
- Reverse voltage protection?: N
- 1. Without any connectors or through-hole capacitors.
- 2. Typical results with 100% duty cycle at room temperature.
- 3. Bidirectional centered at 2.5 V with VCS of 5 V.
- 4. Higher frequencies are possible, but duty cycle will be limited by dead time of approximately 3 μs per cycle.