A family of resonant two-switch boosting switched-capacitor converter with ZVS operation and a wide voltage-gain range

In this paper, a family of Resonant Two-switch Boosting Switched-capacitor Converters (RTBSCs) with ZVS operation and a wide voltage-gain range is proposed. By adding a small resonant inductor to the TBSCs, the two bulky capacitor banks can be replaced by two much smaller resonant capacitors. Further by operating it above the resonant frequency, the transistors are ZVS turned on and diodes are ZCS turned off. The soft switching operation makes it possible to increase the switching frequency without sacrificing the overall efficiency, so the size can be decreased. Moreover, the voltage-gain range of the RTBSCs is increased significantly. As a result, the input-voltage range can be increased if the output voltage is regulated. The operation principle, voltage-gain curves, output characteristics and the voltage/current stress of the resonant tank for this family are analyzed. A 3X RTBSC prototype rated at 20~130W with a peak efficiency 98% was built to verify the analysis.