Pololu G2 High-Power Motor Driver 24v21 - 21A

This discrete MOSFET H-bridge motor driver enables bidirectional control of one high-power DC brushed motor. The small 22 x 33mm board supports a wide 6.5 V to 40 V voltage range and is efficient enough to deliver a continuous 21 A without a heat sink. Additional features of this second-generation (G2) driver include reverse-voltage protection along with basic current sensing and current limiting functionality.

Quick Spec

• Motor channels: 1
• Minimum operating voltage: 6.5V
• Maximum operating voltage: 40V
• Continuous output current per channel: 21A
• Current sense: 0.02 V/A
• Maximum PWM frequency: 100 kHz
• Minimum logic voltage: 1.8 V
• Maximum logic voltage: 5.5 V
• Reverse voltage protection?: Y

Pinouts

The logic connections are designed to interface with 1.8 V to 5 V systems (5.5 V max). In a typical configuration, only PWM and DIR are required.

Warning: This motor driver has no over-temperature shut-off. An over-temperature or over-current condition can cause permanent damage to the motor driver. You might consider using either the driver’s integrated current sense output or an external current sensor to monitor your current draw.

Current Limiting

The current limiting threshold is nominally set to about 50 A by default. You can lower the limit by connecting an additional resistor between the VREF pin and the adjacent GND pin; the graph below shows how the current limit relates to the VREF resistor value. For example, adding a 100 kΩ resistor between VREF and GND lowers the current limit to approximately 29 A. Note that the current limiting threshold is not highly precise (we have seen some units limit the current as low as about 40 A when the threshold is set to the board’s default of 50 A), and it is less accurate at especially low settings (indicated by the dashed portion of the curve).

Resources

• Product Page

Code

Shipping List

• 1 x Pololu G2 High-Power Motor Driver 24v21
• 2 x 8 Way SIP Headers
• 2 x Terminal blocks