Sub-1V Input Single-Inductor Dual-Output (SIDO) DC-DC Converter with Adaptive Load-Tracking Control (ALTC) for Single-Cell-Powered System

Abstract

In this paper, a sub-1V input single-inductor dual-output (SIDO) DC-DC converter with an adaptive load-tracking control (ALTC) technique is proposed for single-cell-powered portable devices. The ALTC technique adaptively and accurately adjusts storage charge in form of the inductor current according to actual load condition without wasting surplus charge and increasing cross-regulation through the use of minimized the number of switch and optimum current sequence. A current-mode ring oscillator with a self-bias current source (SBCS) circuit is proposed to replace conventional startup oscillator to produce a nearly constant system clock. The test chip was fabricated by TSMC 0.25 mu m 2.5 V/5 V BCD process and experimental results show a high efficiency of 92 % and a cross- regulation smaller than 10 mV.