D03.2 - 2:1 Capacitively-Isolated Resonant Switched Capacitor DCX Converter

Power electronics systems have traditionally achieved isolation through magnetic transformers. Although this is a well-understood and straightforward solution, magnetic components remain one of the fundamental bottlenecks in modern power converters. Even though new semiconductor technology has allowed converters to reach the higher frequencies, non-ideal effects in magnetic components prevent them from operating at these ranges. In this context, topologies that reduce or avoid magnetic components are desirable to achieve high power density. In this regard, Switched-Capacitor (SC) converters are an interesting alternative, due to their lack of magnetic components. This paper presents a novel Capacitively Isolated Resonant Switched-Capacitor (ReSC) with a fixed 2:1 gain DC/DC transformer (DCX) which provides isolation through synergy between the resonant tank and the GaN parasitic capacitances. The converter reaches 96% efficiency at 110W with full Zero Voltage Switching (ZVS) in all its switches. Experimental results show that the circuit maintain less than 250 μA of current, validating the original idea of a capacitively isolated topology.