Modeling and Analysis of Resonant Switched-Capacitor Converters with Finite Terminal Capacitances

Abstract

In pre-existing modeling and analysis of resonant switched-capacitor (ReSC) converters, input and output capacitances (C <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in</inf> and C <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">out</inf> ) have long been assumed to be sufficiently large to ensure ideal input and output behaviors. However, this paper reveals that, in practical applications, finite terminal ca-pacitances can have considerable effects on the output impedance and efficiency of ReSC converters. This paper proposes a general modeling and analysis methodology that can characterize the effects of finite terminal capacitances on the output impedance of ReSC converters. The proposed model is verified by circuit simulations and experimental measurements from a 2-to-1 ReSC converter prototype. It is revealed that the insufficiency in terminal capacitances can result in higher critical switching frequency, and C <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in</inf> has stronger influence on the critical switching frequency than C <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">out</inf> .