Digital Implementation of Driving Scheme for Synchronous Rectification in LLC Resonant Converter

摘要

In this paper, a digital implementation of synchronous rectification (SR) driving scheme for LLC resonant converter is proposed. Compared with analog ones, digital implementation could significantly improve efficiency, since it controls dead time more intelligently and precisely. In this LLC resonant converter SR driving scheme, the drain to source voltage of synchronous rectifier on the secondary side is sensed, that is, the paralleled body diode conduction status would be detected. The SR turn-off time is tuned based on the paralleled body diode conduction information. The whole digital tuning system is realized in Cyclone HI FPGA.