Patent ID: 6583993
Filing Date: 2003-06-24
Classification: H02M,Y02B

Abstract:
A self-driven synchronous rectifier circuit, comprising:an input terminal for receiving a voltage; a first power switch electrically connected to the input terminal; a second power switch electrically connected to the input terminal; a transformer having a primary winding, a secondary winding and an independently coupled auxiliary winding, the primary winding being connected to the first power switch and the second power switch; a first synchronous rectifier connected to the first power switch via coupling between the primary and secondary windings of the transformer; a second synchronous rectifier connected to the second power switch via the coupling between the primary and secondary windings of the transformer; a first diode connected to the second synchronous rectifier; and a second diode connected to the first synchronous rectifier, wherein the auxiliary winding is connected to respective gates of the first and second synchronous rectifiers to ensure that the first and second synchronous rectifiers are supplied with an adequate gate drive voltage, and wherein the first and second diodes are operable to prevent the first and second synchronous rectifiers from conducting at the same time.