Hybrid power managemet IC design combining SC converter

Abstract

In this paper, we propose a hybrid DC-DC converter combined with a switched-capacitor that can be used in battery-powered applications. Firstly, we proposed a step-up/down converter powering disposable IoTs with reconfigurable alkaline battery cells from 1xBAT to 3xBATs. The proposed topology enables its input/output currents to be continuous, resulting in reduced power loss at DCRs of inductor and battery. By virtue of battery cell balancer (BCB) in this chip, all energies can be fully extracted from multiple cells. The chip shows 96.8% peak efficiency, and the extended battery time of +12.5% is expected compared to prior works. Nextly, a ±15V bipolar-output high step-up SC DC-DC converter with energy-recycled regulation is presented. An energy-recycled fine regulation scheme with wide VCR is proposed in SC step-up converter. It accurately controls the dropout voltage of post-regulator to be minimal to reduce power loss. Such improvements were achieved without increasing the complexity (cost) overhead or the power loss in the SC circuit. Also, the proposed voltage/currenthybrid (VIH) post-regulator offers high suppression of switching ripple and noise while maintaining a voltage efficiency of 98.7%. The fabricated chip offers 28.7μVRMS output noise and a total peak efficiency of 90.5%.