A Capacitively-Isolated Dual Extended LC-tank Hybrid Switched-Capacitor Converter

Abstract

This work introduces a resonant Dickson-type converter topology whose flying capacitors provide dielectric isolation between input and output terminals. For even conversion ratios, it achieves complete soft-charging of all of its flying capacitors with a convenient 50% duty cycle. Additionally, switch count is reduced relative to prior work and no distributed bypass capacitor column is required. Moreover, this topology actively drives both of its inductors without the requirement for mutual coupling between magnetic elements. A discrete 4:1 hardware prototype designed for 48 V up to rectified US mains applications is demonstrated and achieves a high power density of 2,010 W/in 3 with a 140 V input voltage and 941 kHz switching frequency.

Large Signal Analysis on Variations of the Hybridized Dickson Switched-Capacitor Converter

“…As a result, these structures allow for very large ripple, with [7] demonstrating flying capacitors being exercised over almost their entire dielectric range. In addition, the dielectric barrier of resonant tanks may find a two-fold use in capacitively isolated designs [41], [42]. Regulation may often be achieved using phase shiftedoperation while preserving ZVS over a known operating range [41], or by modulating the converters output impedance using DOTM [40].…”