Near-independently regulated 5-output single-inductor DC-DC buck converter delivering 1.2W/mm2 in 65nm CMOS

For minimizing the power consumption in portable devices, efficient DC-DC converters with a wide range of regulated voltages and currents are needed. Considering the required footprint area, cost, and chip count, integration of single-inductor-multiple-output (SIMO) DC-DC converters into the system, particularly in scaled CMOS processes, is highly desirable. However, the cross regulation and low power density of SIMO solutions are obstacles to system integration [1-5]. Another problem is the capability of handling high battery voltage in advanced CMOS processes. This paper presents control and circuit techniques used in a 65nm CMOS SIMO buck converter with near-independently regulated five outputs and high power density.