Investigation of high frequency effects on soft-switched synchronous rectifier buck converter

Abstract

This paper discusses about the effects of switching frequency where reduction in losses is significant to the converter's performance. The proposed zero-voltage-switching synchronous buck converter circuit is compared with the conventional synchronous buck converter by applying different frequency ranging from 250 kHz to 1.25 MHz. PSpice simulation is carried out using fixed delay control scheme. It is found that the proposed circuit improves the switching speed by at least 50 % in both turn-off and turn-on transitions. In addition, more than 57 % in switching losses have been reduced. Having a low body diode conduction time, the proposed converter can maintain low loss with minimized dead time delay, indicating suitability in operating at high switching frequency.