How to Use L6203: Examples, Pinouts, and Specs

The L6203 is a dual H-bridge driver manufactured by ICH (Part ID: H-Brücke L6203). It is designed for driving DC motors and stepper motors, offering precise control over motor direction and speed using PWM (Pulse Width Modulation) signals. With its ability to handle high current loads, the L6203 is widely used in robotics, industrial automation, and other motor control applications.

• Robotics: Driving wheels or robotic arms
• CNC machines and 3D printers: Stepper motor control
• Conveyor belts and industrial automation systems
• Electric vehicles and motorized toys
• Home automation: Motorized blinds, doors, or windows

The L6203 is a robust and versatile motor driver with the following key specifications:

The L6203 is available in a Multiwatt15 package. Below is the pin configuration:

1. Power Supply: Connect the supply voltage (12V to 48V) to the VS pins (pins 2 and 13). Ensure the power supply can handle the current requirements of your motor.
2. Motor Connections: Connect the motor terminals to the output pins (OUT1, OUT2 for H-bridge A or OUT3, OUT4 for H-bridge B).
3. Logic Inputs: Use the IN1, IN2, IN3, and IN4 pins to control the direction of the motors. These pins accept standard logic levels (0V for LOW, 5V for HIGH).
4. Enable Pins: Set the ENA and ENB pins HIGH to enable the respective H-bridges. Pull these pins LOW to disable the H-bridges.
5. PWM Control: Apply a PWM signal to the logic input pins (IN1, IN2, IN3, IN4) to control motor speed.
6. Current Sensing (Optional): If current sensing is required, connect a resistor between the Vref pin and ground. The voltage across this resistor will be proportional to the motor current.

• Heat Dissipation: The L6203 can generate significant heat during operation. Use a heatsink or proper thermal management to prevent overheating.
• Decoupling Capacitors: Place a high-value electrolytic capacitor (e.g., 100 µF) and a low-value ceramic capacitor (e.g., 0.1 µF) close to the VS pins to stabilize the power supply.
• Protection Diodes: The L6203 includes internal freewheeling diodes for motor back-EMF protection. However, additional external diodes may be added for extra safety in high-current applications.

Below is an example of how to control a DC motor using the L6203 and an Arduino UNO:

• Connect VS to a 12V power supply.
• Connect OUT1 and OUT2 to the motor terminals.
• Connect IN1 and IN2 to Arduino digital pins 9 and 10, respectively.
• Connect ENA to Arduino digital pin 8.
• Connect GND to the Arduino GND.

// Define pin connections
const int ENA = 8;  // Enable pin for H-bridge A
const int IN1 = 9;  // Logic input 1 for H-bridge A
const int IN2 = 10; // Logic input 2 for H-bridge A

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

  // Enable the H-bridge
  digitalWrite(ENA, HIGH);
}

void loop() {
  // Rotate motor in one direction
  digitalWrite(IN1, HIGH);
  digitalWrite(IN2, LOW);
  delay(2000); // Run for 2 seconds

  // Stop the motor
  digitalWrite(IN1, LOW);
  digitalWrite(IN2, LOW);
  delay(1000); // Pause for 1 second

  // Rotate motor in the opposite direction
  digitalWrite(IN1, LOW);
  digitalWrite(IN2, HIGH);
  delay(2000); // Run for 2 seconds

  // Stop the motor
  digitalWrite(IN1, LOW);
  digitalWrite(IN2, LOW);
  delay(1000); // Pause for 1 second
}

1. Motor Not Spinning

   • Ensure the ENA pin is set HIGH to enable the H-bridge.
   • Verify the power supply voltage and current are sufficient for the motor.
   • Check the logic input connections (IN1, IN2, etc.) and ensure they are receiving the correct signals.

2. Overheating

   • Use a heatsink or active cooling to manage heat dissipation.
   • Reduce the motor load or operating current if possible.

3. Erratic Motor Behavior

   • Add decoupling capacitors near the VS pins to stabilize the power supply.
   • Check for loose or faulty connections in the circuit.

Q: Can the L6203 drive two DC motors simultaneously?
A: Yes, the L6203 has two H-bridges, allowing it to drive two DC motors independently.

Q: What is the maximum PWM frequency supported?
A: The L6203 supports PWM frequencies up to 100 kHz.

Q: Do I need external diodes for motor back-EMF protection?
A: The L6203 includes internal freewheeling diodes, but external diodes can be added for additional protection in high-current applications.