A Burst-Mode Control Method for Phase-Shift Controlled Switched-Capacitor-Based Resonant Converters

This paper proposes a burst-mode control method for phase-shift controlled switched-capacitor-based resonant converters (SCRCs) to improve the efficiency under light load conditions. The proposed burst-mode control method adjusts the burst frequency to achieve the highest conversion efficiency with an acceptable level of the peak-to-peak load voltage ripple. A new switching sequence just before the interval has been developed to eliminate high-frequency ringing when the SCRC stops switching. Moreover, the controller also adjusts the SCRC's switching sequence just after the interval to maintain the operation at the optimum efficiency condition. A 3-kW, 360-kHz SCRC prototype was built to verify the proposed burst-mode control method experimentally. As a result, the newly-developed burst-mode control method can maintain a power conversion efficiency higher than 99% without any high-frequency ringing even under light load conditions.