T14.7 - An Output Voltage Maximizer for Efficiency Improvement in Resonant Switched-Capacitor Converters

Resonant switched-capacitor (ReSC) converters have received growing interest due to their ability to attain high power densities and efficiencies, particularly for fixed-ratio voltage conversion. While existing control techniques typically focus on reducing either conduction or switching loss, their benefits are limited since the relative distribution of these losses depends on converter parameters and operating conditions. This paper therefore proposes a feedback controller that leverages the output impedance characteristics of fixed-ratio ReSC converters to optimize their efficiency across line and load variations using only a single voltage sensor. The concept is validated on a 2-to-1 converter with experimental results demonstrating up to $81.9\%$ loss reduction compared to conventional open-loop operation. With simplified sensing requirements and fully digital implementation, the proposed approach offers a practical solution that can be extended to a wide range of ReSC topologies.