DRIVING CIRCUIT OF SYNCHRONOUS RECTIFIER FOR FLYBACK CONVERTER

摘要

PURPOSE: A synchronous rectifier driver circuit for a flyback converter is provided to simplify a structure of a secondary side rectification circuit of the flyback converter by driving a secondary side synchronous rectifier without receiving information about voltage from a first side of the flyback converter. CONSTITUTION: A synchronization pulse generating circuit(201) includes a synchronization resistance(Rsync) and a synchronization diode(Dsync). The synchronization pulse generating circuit generates a synchronization pulse signal for synchronizing a start time of a synchronous rectifier(SR). A turn-on driving voltage generation unit(202) applies synchronous rectifier driving currents to a gate terminal of the synchronous rectifier. A turn-off driving voltage discharge unit(203) discharges voltage, charged in the gate of the synchronous rectifier, to earth.