Design of high-efficiency digital-control multi-topology step-down switched capacitor converter

This paper presents a multi-topology step-down switched-capacitor (SC) converter with a novel digital control. The feedback control system performs digital control over operating frequency and topology of the converter to efficiently modify the SC configuration depending on actual current load as well as required output voltage. The feedback is designed without the usage of reference voltages which provides easy integration of proposed SC converter in digital systems. The converter achieves maximal efficiency of 88%, while providing a wide range of load current and low level of output voltage ripple. Due to the multi-topology structure, high efficiency is provided over 1.3V of input voltage. The converter is designed in 28nm CMOS process using the proposed technique.