An improved gating technique for the synchronous rectifier MOSFETs in the forward converter topology

In this paper self-driven gating techniques for the synchronous rectifiers in a forward converter topology are discussed. Conventional implementations of gatings are investigated and their drawbacks are identified. An improved gating implementation is presented, which forces longer drain to source conduction of the rectifying MOSFET, protects it from excessive negative gate-source voltage stress, and has simple circuitry. A design procedure is presented and the concept is verified experimentally.