The zero voltage switching (ZVS) critical conduction mode (CRM) buck converter with tapped-inductor

This paper proposes a critical conduction mode buck converter that has soft-switching operation by tapped-inductor. In this converter, both the active switch and the diode have soft switching operation by the resonance between the switch parasitic capacitors and the filter inductor. And, the turn-off switching loss of the active switch is reduced by the decrease of the turn-off current. In addition, tapped-inductor changes the conduction operation, which makes some advantageous conditions that diminish the conduction loss and device stresses. Therefore, this topology, ultimately, achieves both the power and cost efficiency by the simple variation of the classical structure. For the proposed converter evaluation, this paper provides the operation analysis of the converter and the hardware verification by 50 W prototype operating at maximum 70 kHz.