【Changsha University of Science and Technology】DC-DC Wang Dongmin

Bidirectional DC-DC converter

This bidirectional DC-DC power converter uses the most commonly used modulation method, isolated PWM control, to achieve stable voltage output using wide-range voltage and current devices.

This enables the circuit to have a wide input and output voltage and current range and meet more requirements.

Selection of key originals

1. Use LM358 (widely used, stable performance, high input impedance) dual power supply operational amplifier, use resistors to divide the voltage through the amplifier circuit and the voltage follows the current.

The circuit is used to collect the output voltage, and at the same time it increases the input impedance to avoid affecting the measured voltage value .

2. In the control circuit, in order to protect system safety and avoid interference, ADUM1300B isolation chip is used to conduct electrical conduction between input and output, input and ground.

Air isolation thereby improves the stability of the circuit.      

3. The loss of switching tubes is inevitable, so low-power switching tubes and diodes are selected. Use MOS tube as switching tube, IRF540 type MOS tube

The switching loss is small and can well meet the circuit requirements.

4. Using Schottky diode as the freewheeling diode has high voltage resistance and low loss, which can reduce the loss of switching devices and better improve system efficiency.

Through each debugging, the layout is gradually changed to make each new version of the Shuxiang DC-DC circuit more perfect, reducing the connection of switch signals, making the switch

The signal should be routed to minimize loss as much as possible.