Single-inductor multiple-output DC-DC buck converter

Battery-operated electronic products have the trend of compact size, longer battery usage, and thinner form factor. It leads to the development of system-on-a-chip (SoC) because the SoC can merge different kinds of digital and analog circuits into one fabricated chip to enhance circuit performance and to reduce the printed-circuit board (PCB) area. 44Generally speaking, the SoC is composed of many functional blocks including microprocessor, digital signal processor, random access memory, read-only memory, analog-to-digital and/or digital-to-analog converter, input/output control circuits, and today’s key energy controlling module-power management unit (PMU) [1-22].