advantage
1 The duty ratio is arbitrarily adjustable;
2 isolation withstand voltage is high;
3 Strong anti-interference ability, currently optocoupler with electrostatic shielding is easy to buy, the isolation performance between strong and weak electricity is very good, in addition, optocoupler is a current-type device, which can effectively suppress voltage noise;
4 Transmission signals range from DC to several MHz, where linear optocouplers are especially suitable for signal feedback.
Disadvantage
  1 In the full-bridge topology, there are 4 switching devices, which require 3-4 optocouplers, and each optocoupler needs independent power supply, which increases the complexity of the circuit, increases the cost, and reduces the reliability.
2 Due to the large delay of optocoupler transmission, in order to ensure the accuracy of switching device turn-on and turn-off, the structural parameters of each channel must be made consistent, so that the delay of each channel is consistent, which is often difficult to do well;
The switching speed of the optocoupler is slow, which causes a large delay to the front and rear edges of the drive pulse, which affects the control accuracy.