DRV8424P - How it works
This is a DRV8424P dual motor H-bridge driver breakout designed to control two brushed DC motors or one bipolar stepper motor. It uses the DRV8424P driver from Texas Instruments, which allows for bidirectional control, adjustable current regulation, and low power sleep mode.
Datasheet
For detailed technical information, refer to the official DRV8424P datasheet:
DRV8424P Datasheet
Technical documentation for the DRV8424P H-bridge driver
What does the DRV8424P do?
The DRV8424P enables efficient, precise control of two DC motors or one bipolar stepper motor. It offers peak currents up to 2A per H-bridge and supports both PWM and PH/EN control schemes. The device includes several protections:
- Overcurrent protection
- Undervoltage lockout
- Overtemperature shutdown
- Fault indication pin (FAULT)
It operates over a wide voltage range (4.5V to 33V) and supports fast switching thanks to its internal low-RDS(on) FETs.
Motor control overview
Each H-bridge (A and B) is driven by a pair of logic pins:
- IN1 / IN2: Sets the direction and speed via PWM or logic level.
- SLEEP: An active-low pin used to put the driver into low-power mode.
- FAULT: An open-drain, active-low output that signals a fault condition.
To control a DC motor, connect it to the OUT1 and OUT2 pins of one H-bridge. To control a stepper motor, use both H-bridges simultaneously: one for coil A and one for coil B.
Example configuration
For typical brushed DC motor usage:
- AIN1 / AIN2 and BIN1 / BIN2 are controlled via PWM or logic levels to adjust speed and direction.
- Pull SLEEP high to activate the driver.
- Monitor FAULT for safety issues.
For a bipolar stepper motor:
- Use both A and B bridges to control coil pairs.
- A common sequence (e.g., full-step, half-step, microstepping) energizes each pair accordingly.
Output Behavior Table (per H-bridge)
| IN1 | IN2 | Motor Behavior |
|---|---|---|
| 0 | 0 | Coast (Hi-Z) |
| 0 | 1 | Reverse |
| 1 | 0 | Forward |
| 1 | 1 | Brake (Low output) |
Applications
- Robotics
- Automated gates
- CNC and 3D printers
- General motorized systems