Novel synchronous rectification strategy for flyback converter in both DCM and CCM applications

Abstract

AbstractIn this paper, a novel flyback synchronous rectification (SR) strategy for both continuous conduction mode (CCM) and discontinuous conduction mode (DCM) is proposed. The hybrid mode is suitable for the wide input voltage range, and large load range, which can widen the application range. The proposed strategy can reduce the body diode conduction time in the turning‐on interval in both the DCM and CCM and eliminate the cross‐conduction between the primary switch and secondary switch that existed in the conventional CCM SR converter by adding several logic units. A 12‐V/3‐A output mixed‐mode flyback converter prototype is designed and fabricated to verify the strategy. Measurement results show that with the proposed SR strategy, the efficiency is improved by approximately 5.5% in CCM and 0.5% in DCM.