Analysis and Design of a Modified Triple-mode Resonant Switched-capacitor Converter with Hybrid Modulation Scheme

In this paper, a modified triple-mode resonant switched-capacitor converter (RSC) with phase-shift and variable frequency hybrid modulation scheme is analyzed and designed. All the transistors can be operated with zero voltage switching (ZVS) turn-on, reducing switching loss significantly. Based on the comprehensive operation principle analysis, state-plane trajectory, a modulation scheme is proposed to provide a guideline for converter operation in the low circulating current region and to improve the light-load operation performance. It is shown that both the switching frequency and phase-shift range can be modulated to regulate the output voltage continuously and widely. A 48 V to 100V-160V open loop prototype with power level 70-170W, frequency range 90-140 kHz and peak efficiency 98.4% was built to verify the operation of the converter.