Active Clamped Resonant Flyback with a Synchronous Rectifier

摘要

A zero-voltage-switching (ZVS) resonant flyback converter with a synchronous rectifier is presented in this paper. An active clamp circuit is added to the conventional flyback converter to clamp the voltage across the switches and provide ZVS operation. By utilizing a resonance between the leakage inductance of a transformer and a clamp capacitor, the energy stored in the primary side is transferred to the secondary side with a resonant manner. Therefore, the output rectifier is turned off softly. Moreover, a synchronous rectifier is adopted at the secondary side to improve the efficiency. The operation principle and steady-state analysis of the proposed converter are provided. A prototype of the proposed converter is developed, and its experimental results are presented for validation.