The full-bridge driver is a commonly used circuit for driving motors or other loads. It consists of two complementary parallel transistors, known as the upper bridge arm and the lower bridge arm. When the upper bridge arm is conducting, the load is connected to the positive power supply, and the load current flows through the upper bridge arm and the load itself. When the lower bridge arm is conducting, the load is connected to the negative power supply, and the load current flows through the lower bridge arm and the load itself. Typically, the conduction and non-conduction of the upper and lower bridge arms are controlled by PWM levels.
The advantages of full-bridge driver include:
1. All-directional and bidirectional control: The full-bridge driver can control the motor's forward, reverse, and stop motion. It can flexibly control the movement direction of the load.
2. High voltage efficiency: The full-bridge driver can efficiently drive the load using the input power supply's voltage, reducing energy losses.
3. Strong controllability: By adjusting the duty cycle of the PWM signal, the size of the load current can be accurately controlled, achieving precise control of the load.
The disadvantages of a full-bridge driver include:
1. High complexity: The design and control of a full-bridge driver are relatively complex, requiring proper control of the on and off states of the upper and lower bridge arms.
2. High cost: Due to the need for two transistors and PWM control circuits, a full-bridge driver has a higher cost.
Common applications of full-bridge drivers include single-phase DC motors, stepper motors, and DC brushless motors. Full-bridge drivers are widely used in embedded systems for industrial automation, robotic control, electric vehicles, aerospace, and other fields.