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

• Published in: IEEE transactions on power electronics 2010-07, Vol.25 (7), p.1713-1724
• Main Authors: HUANG, Ming-Hsin, TSAI, Yu-Nong, CHEN, Ke-Horng
• Format: Article
• Language: English
• Subjects: Adaptive control; Adaptive control systems; Adaptive load-tracking control (ALTC) technique; Applied sciences; Circuit properties; Circuits; Clocks; CMOS; Control; Control systems; Converters; dc-dc converter; DC-DC power converters; Devices; Efficiency; Electric, optical and optoelectronic circuits; Electrical engineering. Electrical power engineering; Electronic circuits; Electronics; Energy storage; Exact sciences and technology; Frequencies; Inductors; Magnetic devices; Oscillators; Power electronics, power supplies; Programmable control; Ring oscillators; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Semiconductors; Signal convertors; single-cell-powered systems; single-inductor dual-output (SIDO) self-bias current source (SBCS) circuit; sub-1 V input; Switches; Switching; Transformers and inductors
• ISSN: 0885-8993; 1941-0107
• DOI: 10.1109/TPEL.2010.2042073

In this paper, a sub-1 V input single-inductor dual-output (SIDO) dc-dc converter with an adaptive load-tracking control (ALTC) technology is proposed for single-cell-powered portable devices. Having a minimal number of switches and an optimum current sequence, the proposed ALTC technique adaptively and accurately adjusts storage energy in the form of inductor current according to the actual load condition, without wasting surplus charge and without increasing cross regulation. Moreover, a current-mode ring oscillator with a self-bias current source circuit, in place of the conventional start-up ring oscillator, is proposed to produce a nearly constant system clock for the requirement of sub-1 V start-up procedure. Because the proposed current-mode ring oscillator operates between the start-up process and steady state of the SIDO dc-dc converter, its simplified design efficiently addresses the high switching frequency losses at sub-1 V start-up procedure, reducing chip area and power consumption. The proposed sub-1 V input SIDO dc-dc converter was fabricated via Taiwan Semiconductor Manufacturing Company 0.25 μm 2.5 V/5 V Bipolar-CMOS-DMOS process, and the experimental results show high efficiency of 92% with a good cross regulation smaller than 10 mV.