A General Analysis of Resonant Switched-Capacitor Converters Using Peak Energy Storage and Switch Stress Including Ripple
Nathan M. Ellis, Nathan C. Brooks, Margaret E. Blackwell, Rose A. Abramson, Samantha Coday, Robert C. N. Pilawa-Podgurski
Abstract
This work presents a general analytical framework enabling large-signal characterization of resonant switched-capacitor (ReSC) power converters that accounts for passive component voltage and current ripple, for operation at and above resonance. From this, appropriate phase durations for minimized rms currents are derived, in addition to expressions for total passive component volume using an intuitive peak energy method. An example hardware prototype validates both the derived waveforms and timings—as well as total passive volume—through three comparable hardware configurations, one of which minimizes passive component volume. In addition, the proposed technique formulates analytical expressions for both rms currents and peak blocking voltages, facilitating refined loss estimation and component selection. Subsequent calculation of the large-signal Volt–Amp (VA) switch stress metric allows a more accurately quantified trade-off between active and passive components compared to prior work, which has not fully accounted for ripple. Four common ReSC topologies are exemplified throughout, with topology specific parameters documented for reference.