A Comparison of Bridgeless and Full Bridge Buck Converters Operating at DICM and DCVM

This study compares three types of high efficiency, high power factor (HPF) step-down (Buck) AC-DC converters: (1) bridgeless Buck operating in discontinuous inductor current mode (DICM), (2) conventional full bridge Buck operating in discontinuous capacitor voltage mode (DCVM), and (3) bridgeless Buck operating in discontinuous capacitor voltage mode (DCVM). Low switching losses, smaller heat sinks for the switching components, and reduced electromagnetic interference (EMI) noise emissions from the output diode and power switches' zero-voltage turn-offs are some of the additional benefits of DCVM operation. As a result, the study highlights the benefits of bridgeless topology and DCVM converters, which naturally produce a high-power factor (nearly unity power factor) with low total harmonic distortion (THD) international standards, i.e. IEC 61000-3-2 Class D requirements [1].