A high efficiency gate-driving scheme of synchronous rectifiers in Wide-Input-Voltage-Range CCM Flyback Converter

A new gate-driver scheme is proposed in this paper to improve the efficiency of the synchronous rectifiers in wide-input-voltage range Flyback converter. The proposed new gate-driver scheme bases on the auxiliary windings and an additional control switch, which connects in parallels with the Flyback main circuits and synchronous rectifier. The driving signals are synchronized properly through the auxiliary windings of the power transformer can optimize MOSFET turn-on and turn-off delays in synchronous rectifiers. The driving signal prevents the MOSFET body-diode to conduct and continuously adjusts to minimize the cross-conduction time interval. The operation principle and experiment results are presented in this paper.