Analysis and Design of Four-Level Flying-Capacitor Converter in Burst Mode Operation

Abstract

The design analysis and loss model of the four level flying capacitor converter in burst mode operation is introduced. Detailed analysis of the proposed converter including operating mode, charge balance characteristic, and loss estimation for optimum efficiency are given. One shot injected burst mode operation is also proposed which can reduce the voltage ripple of the flying capacitor. The proposed scheme and analysis are verified by the simulation study. The simulation results with the input voltage range of 3-5V (for Li-Ion battery), the output voltage range of 0.6-V1.2V(typical supply voltage of digital circuits), 1mA < load current <1 .5A shows the verification of the full-time active balancing scheme and the ripple minimization of the proposed technique.