Zero-voltage-switching techniques and their application to high-frequency converter with piezoelectric transformer

This paper classifies the zero-voltage-switching, clamped-voltage (ZVS-CV) topologies for high-frequency switching dc-dc converters. These topologies are suitable for high-frequency operation because they can suppress the switching loss and voltage stress to the switching elements. In order to demonstrate this feature, we applied a ZVS-CV topology to the high-frequency dc-dc converter with a piezoelectric transformer which operates in megahertz frequency region. In our experiments, the efficiency of 77.8% at the switching frequency of 1.3 MHz was obtained