Secondary side post regulator for improving cross regulation and reducing standby power consumption

Abstract

The quest for improved energy savings is driving research into power converter high-efficiency operation under extremely light-load conditions. The use of multiple output converters to satisfy circuit needs and cost requirements adds additional complication to the standby mode power-consumption problem. This is due to the difficulty of satisfying both good cross-regulation under various load conditions as well as high efficiency in the standby mode simultaneously; because topologies that exhibit a good cross-regulation performance, such as resonant converters, generally have a poor efficiency problem under extremely light-loads. A secondary side post regulator (SSPR) is proposed to reduce the standby power consumption and to improve the cross-regulation performance of single-controller multiple-output channel power converters. It is capable of reducing the power consumption of the power converter as well as the SSPR. The SSPR is analysed using its operational principles and small signal models. A 110 W experimental prototype was built to verify the standby power consumption and cross-regulation performance using the proposed SSPR.