A Family of Dual Resonant Switched-Capacitor Converter with Passive Regenerative Snubber

In this article, a step-down switched-capacitor converter (SCC) and a step-up SCC with an integrated passive regenerative snubber (PRS) are proposed based on the Cuk dual resonance core (DRC). The members of the DRC converter family overcome the barrier for SCCs to achieve continuous output voltage regulation. One remaining challenge is the turn-off spikes and oscillations during the switch turn-off transient that cause voltage stress and power loss to the transistor and diode. The proposed integrated PRS eliminates voltage spikes and oscillations across the transistor and diode during the turn-off process. Moreover, zero voltage switching (ZVS) turn-on for the clamped mosfet, zero current switching (ZCS) turn-on for the other mosfet and ZCS turn-off for all diodes are achieved. A comprehensive analysis of the operation principle, conversion ratio curves, component stress, and regenerative power of the proposed converters with regenerative snubbers is given. Furthermore, a performance comparison between the proposed snubber configuration and two conventional methods is given. A 50 V/99.25 V step-up converter prototype of 125 W has demonstrated a peak efficiency of 98.4%. The analysis is verified by both simulation and experiments.