A 1.2A auto-configurable dual-output switched-capacitor DC-DC regulator with continuous gate-drive modulation achieving <0.01mV/mA cross regulation

An auto-configurable dual-output switched-capacitor DC-DC regulator for portable applications is presented in this paper. With 100s-of-mA load per output, a continuous gate-drive modulation scheme is proposed not only to minimize output cross regulation under load-step transient, but also to reduce output voltage ripple with small output capacitance. An all-nMOS reconfigurable power stage, together with sharing of flying capacitors and power transistors between outputs, is developed to improve both board and chip area efficiency of the regulator. Implemented in a 0.13μm CMOS process, the proposed regulator generates two outputs of 0.8V and 1.6V, supports 600mA/output load with only a 2.2μF output capacitor, and offers 87.6% peak power efficiency. Compared to state-of-the-art single-inductor multiple-output DC-DC converters, the proposed SC regulator improves the output cross regulation by >4× with larger load steps and smaller load capacitance/output.