How to Use TB6612FNG: Examples, Pinouts, and Specs

The TB6612FNG, manufactured by Pololu, is a dual H-bridge motor driver IC designed for controlling two DC motors or one stepper motor. It supports PWM (Pulse Width Modulation) for precise speed control and direction management. With a compact design and robust performance, the TB6612FNG is widely used in robotics, automation, and other motor control applications.

• Robotics: Driving wheels or actuators in mobile robots.
• Automation: Controlling conveyor belts or small machinery.
• DIY Projects: Motorized toys, RC vehicles, and hobbyist electronics.
• Stepper Motor Control: Driving stepper motors in CNC machines or 3D printers.

• Operating Voltage (Vcc): 2.5V to 13.5V
• Logic Voltage (Vcc for logic): 2.7V to 5.5V
• Output Current (per channel): 1.2A (continuous), 3.2A (peak)
• Control Method: PWM (up to 100 kHz)
• Standby Current: 1 µA (typical)
• Thermal Shutdown Protection: Yes
• Overcurrent Protection: Yes
• Operating Temperature Range: -20°C to +85°C
• Package Type: SSOP24

The TB6612FNG has 24 pins, but the most commonly used pins for motor control are listed below:

1. Power Connections:

   • Connect the logic voltage (2.7V to 5.5V) to the VCC pin.
   • Connect the motor power supply (2.5V to 13.5V) to the VM pin.
   • Ensure all GND pins are connected to the ground of the circuit.

2. Motor Connections:

   • Connect the motor terminals to AO1/AO2 for Motor A and BO1/BO2 for Motor B.

3. Control Signals:

   • Use AIN1/AIN2 and BIN1/BIN2 to control the direction of Motor A and Motor B, respectively.
   • Use PWMA and PWMB to control the speed of Motor A and Motor B using PWM signals.
   • Set the STBY pin HIGH to enable the IC.

4. PWM Frequency:

   • The TB6612FNG supports PWM frequencies up to 100 kHz. A typical frequency of 20 kHz is recommended for most applications.

Below is an example of how to control two DC motors using the TB6612FNG and an Arduino UNO.

• Motor A:
  • Connect AO1 and AO2 to the terminals of Motor A.
  • Connect AIN1, AIN2, and PWMA to Arduino digital pins 2, 3, and 5, respectively.
• Motor B:
  • Connect BO1 and BO2 to the terminals of Motor B.
  • Connect BIN1, BIN2, and PWMB to Arduino digital pins 7, 8, and 6, respectively.
• Power:
  • Connect VCC to the Arduino 5V pin.
  • Connect VM to an external motor power supply (e.g., 9V battery).
  • Connect all GND pins to the Arduino GND.

// Define motor control pins
#define AIN1 2  // Motor A direction pin 1
#define AIN2 3  // Motor A direction pin 2
#define PWMA 5  // Motor A speed (PWM) pin
#define BIN1 7  // Motor B direction pin 1
#define BIN2 8  // Motor B direction pin 2
#define PWMB 6  // Motor B speed (PWM) pin
#define STBY 4  // Standby pin

void setup() {
  // Set motor control pins as outputs
  pinMode(AIN1, OUTPUT);
  pinMode(AIN2, OUTPUT);
  pinMode(PWMA, OUTPUT);
  pinMode(BIN1, OUTPUT);
  pinMode(BIN2, OUTPUT);
  pinMode(PWMB, OUTPUT);
  pinMode(STBY, OUTPUT);

  // Enable the motor driver by setting STBY HIGH
  digitalWrite(STBY, HIGH);
}

void loop() {
  // Example: Run Motor A forward at 50% speed
  digitalWrite(AIN1, HIGH);
  digitalWrite(AIN2, LOW);
  analogWrite(PWMA, 128);  // 50% duty cycle (128/255)

  // Example: Run Motor B backward at 75% speed
  digitalWrite(BIN1, LOW);
  digitalWrite(BIN2, HIGH);
  analogWrite(PWMB, 192);  // 75% duty cycle (192/255)

  delay(2000);  // Run for 2 seconds

  // Stop both motors
  analogWrite(PWMA, 0);
  analogWrite(PWMB, 0);

  delay(2000);  // Wait for 2 seconds
}

• Ensure the motor power supply (VM) matches the voltage requirements of your motors.
• Use appropriate decoupling capacitors near the power supply pins to reduce noise.
• Avoid exceeding the maximum current rating (1.2A continuous, 3.2A peak) to prevent damage.
• Use heat sinks or proper ventilation if operating near the maximum current for extended periods.

1. Motors Not Running:

   • Ensure the STBY pin is set HIGH to enable the IC.
   • Verify that the motor power supply (VM) is connected and within the specified range.

2. Motor Running in the Wrong Direction:

   • Check the logic levels on AIN1/AIN2 or BIN1/BIN2. Swap the HIGH/LOW signals to reverse direction.

3. Motor Speed Not Changing:

   • Ensure the PWM signal is being generated correctly on the PWMA/PWMB pins.
   • Verify that the PWM frequency is within the supported range (up to 100 kHz).

4. Overheating:

   • Check if the current draw exceeds the IC's maximum rating.
   • Add a heat sink or reduce the load on the motors.

• Can I use the TB6612FNG to drive a stepper motor? Yes, the TB6612FNG can drive a bipolar stepper motor by controlling the two H-bridges independently.

• What happens if the STBY pin is left floating? The IC will remain in standby mode. Always pull the STBY pin HIGH to enable operation.

• Is it possible to control the TB6612FNG with 3.3V logic? Yes, the TB6612FNG supports logic voltages as low as 2.7V, making it compatible with 3.3V systems.