How to Use TB6612FNG Motor Driver: Examples, Pinouts, and Specs

The TB6612FNG is a dual H-bridge motor driver IC designed to control two DC motors or one stepper motor. It supports PWM (Pulse Width Modulation) for precise speed control and direction management. With built-in thermal shutdown protection, overcurrent protection, and low standby current, the TB6612FNG is a reliable choice for robotics, automation, and other motor control applications.

• Robotics (e.g., controlling wheels or arms)
• Automated conveyor systems
• DIY projects involving DC or stepper motors
• Educational electronics kits
• Small-scale industrial automation

The TB6612FNG comes in a 16-pin package. Below is the pinout and description:

1. Power Connections:

   • Connect Vcc to a 3.3V or 5V logic power supply.
   • Connect VM to the motor power supply (4.5V to 13.5V).
   • Connect GND to the ground of the power supply.

2. Motor Connections:

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

3. Control Signals:

   • Use AIN1 and AIN2 to control the direction of Motor A, and BIN1 and BIN2 for Motor B.
   • Provide PWM signals to PWMA and PWMB to control the speed of Motor A and Motor B, respectively.
   • Set STBY HIGH to enable the IC. Pull it LOW to put the IC in standby mode.

4. Direction Control:

   • Set AIN1 HIGH and AIN2 LOW to rotate Motor A in one direction.
   • Set AIN1 LOW and AIN2 HIGH to rotate Motor A in the opposite direction.
   • Similarly, use BIN1 and BIN2 for Motor B.

5. PWM Speed Control:

   • Apply a PWM signal (0-100% duty cycle) to PWMA or PWMB to control the speed of the motors.

Below is an example code to control two DC motors using the TB6612FNG and an Arduino UNO:

// Pin definitions for Motor A
const int AIN1 = 7;  // Direction control pin 1 for Motor A
const int AIN2 = 8;  // Direction control pin 2 for Motor A
const int PWMA = 9;  // PWM speed control pin for Motor A

// Pin definitions for Motor B
const int BIN1 = 4;  // Direction control pin 1 for Motor B
const int BIN2 = 5;  // Direction control pin 2 for Motor B
const int PWMB = 6;  // PWM speed control pin for Motor B

// Standby pin
const int STBY = 10; // Standby control pin

void setup() {
  // Set all 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: Rotate Motor A forward at 50% speed
  digitalWrite(AIN1, HIGH);
  digitalWrite(AIN2, LOW);
  analogWrite(PWMA, 128); // 50% duty cycle (128 out of 255)

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

  delay(2000); // Run motors for 2 seconds

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

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

• Ensure that the motor power supply voltage (VM) matches the motor's rated voltage.
• Do not exceed the maximum continuous current rating of 1.2A per channel.
• Use appropriate decoupling capacitors between VM and GND to reduce noise.
• Avoid running the IC at high currents for extended periods to prevent overheating.

1. Motors Not Running:

   • Ensure STBY is set HIGH to enable the IC.
   • Check the power supply connections for Vcc and VM.
   • Verify that the PWM signals are being generated correctly.

2. Motor Running in the Wrong Direction:

   • Swap the logic levels of AIN1 and AIN2 (or BIN1 and BIN2) to reverse the direction.

3. Overheating:

   • Ensure the current draw of the motors does not exceed 1.2A per channel.
   • Add a heatsink or improve ventilation if the IC gets too hot.

4. No Response to PWM Signals:

   • Verify that the PWM frequency is within the recommended range (typically 20kHz or lower).
   • Check the connections to the PWMA and PWMB pins.

Q: Can the TB6612FNG drive stepper motors?
A: Yes, the TB6612FNG can drive a bipolar stepper motor by controlling the two H-bridges with appropriate step sequences.

Q: What happens if the IC overheats?
A: The TB6612FNG has built-in thermal shutdown protection. It will automatically disable the outputs if the temperature exceeds safe limits.

Q: Can I use the TB6612FNG with a 3.3V microcontroller?
A: Yes, the TB6612FNG supports logic levels as low as 2.7V, making it compatible with 3.3V microcontrollers.