Introduction to Soft Switching

Abstract

This short video presents an introduction to the concepts of hard versus soft switching, zero-voltage switching (ZVS), resonant transitions, zero-current switching (ZCS), and how all of these relate to loss mechanisms in switched-mode power converters. A standard half-bridge configuration is used to illustrate the characteristics of switching transitions and the associated losses under hard-switching conditions. The video then presents a basic soft-switching technique, highlighting how major switching losses, particularly during turn-on, can be significantly reduced through zero-voltage switching. Simulations of a synchronous buck converter are used to compare the loss budget between hard and soft switching scenarios. The video concludes with a summary of the advantages of soft switching, along with important design trade-offs such as increased voltage or current stresses and the potential for higher conduction losses.