EXTERNALLY-DRIVEN SCHEME FOR SYNCHRONOUS RECTIFICATION

摘要

A self-driven synchronous rectifier circuit (50) for a DC-DC power converter. The circuit comprises a primary transformer (16), a first synchronous rectifier (SQ1) coupled to the primary transformer (16), a second synchronous rectifier (SQ2) coupled to the primary transformer (16), an external drive circuit (18). The circuit (50) also comprises a plurality of switches (SQ3, SQ4) controllably coupled to second synchronous rectifier (SQ2). The external drive circuit (18) provides turn-off signaling for both synchronous rectifiers (SQ1, SQ2). Turn-on signaling provided for first synchronous rectifier (SQ1) by the primary transformer (16) turn-on signaling for second synchronous rectifier (SQ2) is provided by the external drive circuit (18).