How to Use DRV8838 Single Brushed DC Motor Driver: Examples, Pinouts, and Specs

The DRV8838 is a single brushed DC motor driver designed to provide efficient and reliable control of a single brushed DC motor. It features a compact design, making it ideal for space-constrained applications. The DRV8838 supports adjustable speed and direction control, and it includes built-in protection mechanisms such as overcurrent protection, thermal shutdown, and undervoltage lockout. This makes it a robust choice for motor control in a variety of applications.

• Robotics and automation systems
• Small electric vehicles
• Industrial equipment
• Consumer electronics
• Educational projects and prototyping

• Operating Voltage Range: 0 V to 11 V
• Output Current: Up to 1.7 A (continuous), 1.8 A (peak)
• Control Interface: PWM (Pulse Width Modulation) and direction control
• Logic Voltage Range: 1.8 V to 7 V
• Built-in Protections:
  • Overcurrent protection
  • Thermal shutdown
  • Undervoltage lockout
• Operating Temperature Range: -40°C to 150°C
• Package Type: 8-pin WSON (3 mm × 3 mm)

The DRV8838 comes in an 8-pin WSON package. Below is the pinout and description:

1. Power Supply: Connect the motor power supply (VM) to the VM pin. Ensure the voltage is within the range of 0 V to 11 V.
2. Logic Inputs: Use the IN1 and IN2 pins to control the motor's speed and direction:
   • Apply a PWM signal to either IN1 or IN2 to control speed.
   • Set IN1 high and IN2 low to rotate the motor in one direction.
   • Set IN1 low and IN2 high to rotate the motor in the opposite direction.
   • Set both IN1 and IN2 low to brake the motor.
3. Sleep Mode: Pull the nSLEEP pin high to enable the driver. Pull it low to put the driver into low-power sleep mode.
4. Fault Monitoring: Monitor the nFAULT pin for fault conditions. If it is pulled low, check for overcurrent, thermal shutdown, or undervoltage issues.
5. Motor Connections: Connect the motor terminals to OUT1 and OUT2.

• Use a decoupling capacitor (e.g., 10 µF) close to the VM pin to stabilize the power supply.
• Avoid exceeding the maximum current rating to prevent damage to the driver.
• Ensure proper heat dissipation, especially in high-current applications.
• Use pull-up resistors on the nFAULT pin if you need to monitor fault conditions.
• For Arduino or microcontroller-based projects, ensure the logic voltage levels are compatible with the DRV8838's input range (1.8 V to 7 V).

Below is an example of how to control a motor using the DRV8838 with an Arduino UNO:

// Define pin connections
const int IN1 = 9;  // PWM pin for motor control
const int IN2 = 10; // Direction control pin
const int nSLEEP = 8; // Sleep mode pin

void setup() {
  // Set pin modes
  pinMode(IN1, OUTPUT);
  pinMode(IN2, OUTPUT);
  pinMode(nSLEEP, OUTPUT);

  // Enable the motor driver
  digitalWrite(nSLEEP, HIGH);
}

void loop() {
  // Rotate motor in one direction at 50% speed
  analogWrite(IN1, 128); // 50% duty cycle (0-255 scale)
  digitalWrite(IN2, LOW);
  delay(2000); // Run for 2 seconds

  // Rotate motor in the opposite direction at 75% speed
  analogWrite(IN1, 0);   // Stop IN1
  analogWrite(IN2, 192); // 75% duty cycle
  delay(2000); // Run for 2 seconds

  // Brake the motor
  digitalWrite(IN1, LOW);
  digitalWrite(IN2, LOW);
  delay(2000); // Brake for 2 seconds
}

1. Motor Does Not Spin:

   • Ensure the nSLEEP pin is pulled high to enable the driver.
   • Verify that the power supply voltage is within the specified range (0 V to 11 V).
   • Check the connections to the motor and ensure they are secure.

2. nFAULT Pin Pulled Low:

   • Check for overcurrent conditions. Reduce the motor load if necessary.
   • Ensure the driver is not overheating. Improve heat dissipation if needed.
   • Verify that the power supply voltage is stable and within range.

3. Motor Spins in the Wrong Direction:

   • Swap the logic levels on the IN1 and IN2 pins to reverse the motor direction.

4. Driver Overheats:

   • Ensure the current draw does not exceed the maximum rating.
   • Use a heatsink or improve ventilation around the driver.

• Can I use the DRV8838 with a 3.3 V microcontroller? Yes, the DRV8838 supports logic voltage levels as low as 1.8 V, making it compatible with 3.3 V systems.

• What happens if both IN1 and IN2 are high? The motor will enter a high-impedance state (coast mode), and it will not actively brake.

• Is the DRV8838 suitable for battery-powered applications? Yes, its low operating voltage and sleep mode make it ideal for battery-powered systems.

• Can I control the speed of the motor? Yes, you can use a PWM signal on the IN1 or IN2 pin to adjust the motor speed.