A Single-Inductor Eight-Channel Output DC-DC Converter With Time-Limited Power Distribution Control and Single Shared Hysteresis Comparator

Abstract

This paper describes a time-limited power distribution control technique that can be used for single-inductor multiple-output (SIMO) DC-DC converter with many unbalanced loads. Furthermore, the true all-comparator control technique that raises no stability or complexity issues is proposed. This all-comparator technique for SIMO converters is realized only with a single shared hysteresis comparator at a constant switching frequency of 800 kHz. This leads to the development of a new inductor peak-current control technique that does not require compensators and a phase-locked loop. This converter is analyzed and compared with existing SIMO converters with respect to the requirements of next-generation power management ICs. The maximum efficiency of the converter reaches 92%. The fabricated chip supporting eight-channel outputs is implemented in a 0.35-mu m CMOS process and occupies an area of 2.4 x 2.1 mm(2).