A Step-down Series-Parallel Dual Resonant Switched-Capacitor Converter with Extended Voltage Gain Range

Abstract

In this paper, a step-down Series-Parallel (SP) Dual Resonant Switched-capacitor Converter (DRSC) is proposed, which is expected to be used for the first stage of a data center. The dual resonant core (DRC) is added to the traditional SP Switched-capacitor Converter (SCC) and the on-time fixed frequency modulation is adopted. Consequently, the resonant inductor current of one resonant tank is overlapped with the other one for a controlled time interval. By varying the overlapped period, the full-range voltage regulation can be achieved efficiently even at light load condition. Moreover, zero-current-switching (ZCS) turn-on for transistors and ZCS turn-off for diodes can be obtained. A comprehensive analysis of the operation principle, voltage-gain curve and component stress is presented. A 3X stepdown SP DRSC prototype with output power of 100W and nominal voltage level of 4SV-I2V was designed and built to verify the operation principle.