A ZVS Soft-Charging Switched-Capacitor Converter

摘要

The trend of power supplies is toward high efficiency and high power density. Switched-capacitor (SC) converter is a good candidate for such trend and attract much attentions in recently years. Therefore, this paper proposes a ZVS soft-charging SC converter for higher efficiency and it is achieved by an auxiliary converter integrated in the converter. The auxiliary converter improves the SC converter's efficiency by stores and recycle the energy produced by the voltage difference in charging and discharging state, as the SC converter without soft charging technique dissipate it as hot. Moreover, the auxiliary converter shapes the charging discharging current waveforms of the flying capacitor, which is beneficial for reducing the conduction losses on the switches. Besides, the auxiliary converter is inherent ZVS turned on the switches of the SC converter. Simulation circuit and experimental prototype with 12 V input 6 V 6 A output 100 kHz switching frequency is built to verify the proposed converters performance. The simulation and experimental results show that the proposed converter is feasibility, and the proposed converter has higher efficiency in all the load range, and the highest efficiency is as high as 98.83%.