Analog Digital Mixed Synchronous Rectifier Gate Signal Generation for LLC Resonant DC/DC Converter

Synchronous rectifier (SR) is extensively applied solution in the power converter since it can reduce the power loss caused by diode. The application of wide bandgap device introduces challenges into the SR due to their fast-switching speed. Aiming at addressing this problem, in this paper, an analog-digital mixed synchronous rectifier gate signal generation for LLC resonant DC/DC converter is proposed. In order to generating accurate SR gate signal for high-frequency LLC converter, a gate signal generation circuit based on high-speed and low propagation delay analog and digital devices is designed. To validate the feasibility of the proposed method and assess the effect on overall efficiency improvement, a 3.7 kW/400V LLC resonant PLECS simulation model and experimental prototype are established. Both simulation and experiment results have validated the functionality of the proposed SR circuitry.