A Dual-Comparator based Low-Cost Low-Ripple Buck DC-DC Converter

A dual-comparator based low-cost low-ripple buck DC-DC converter is designed in 65-nm CMOS, with a quiescent current of 38 $\mu \mathrm{A}$. By using digital switches and a multiplexing comparator, the error comparator and peak-voltage comparator are combined into a single module with low complexity. The input voltage of 3.3 V is converted to an output voltage of 1.5 V, with the peak efficiency of 94% and load regulation of 0.15%, under the load current changes from 1 mA to 50 mA. The circuit is simple and only includes logic control, power driver, power stage, multiplexing module and zero-voltage comparator. The proposed converter has a maximum output ripple of 5.7 mV under $\pm 10\%$ supply variations, -40-90 °C temperature range and different process corners.