A low-power, high-resolution ZCS control for inductor-based converters

Abstract

This chapter presents an improved zero current switching (ZCS) control for high-gain inductor-based DC-DC converter targeting thermoelectric generator (TEG) for wearable electronics. The proposed ZCS control is an all-digital circuit that utilizes a simple finite state machine (FSM) and a 3-bit counter to locate the zero current point. In addition, an efficient push-pull circuit along with delay capacitance banks is used to tune the delay near the zero current point to reduce the estimated error. The proposed control circuit achieves 56 delay steps using 3 control bits while having a high resolution, which helps in maintaining the efficiency of the converter. The prototype chip is fabricated in 65 nm CMOS and occupies an area of less than 0.04 mm.