Multi-Resonant Compensation Control for Terminal Capacitance Reduction in Resonant Switched-Capacitor Converters

In resonant switched-capacitor (ReSC) converters with the conventional two-phase control, input and output capacitors (C
in
and C
out
) need to be sufficiently large to ensure ideal input and output behaviors. However, the bulky terminal capacitors dramatically increase the overall converter volume and significantly limit the potential of ReSC converters for achieving higher power density. This paper proposes a multi-resonant compensation control (MRCC) technique for ReSC converters that can adaptively compensate for the negative effects of finite terminal capacitances by ensuring multi-resonant and full zero current switching (ZCS) operation with adjusted duty ratio and switching frequency. The proposed technique is verified experimentally in a 2-to-1 ReSC converter prototype, demonstrating a more than 5 times terminal capacitance reduction without harming the overall efficiency compared to the conventional control technique.