A 12nA Quiescent Current and 86.2% Light-Load Efficiency Buck Converter with Sleep Time Control for IoT Applications

This paper presents a low-power constant on time (COT) controlled buck converter with improved light load efficiency. A voltage sampling and holding circuit and a sleep control circuit are adopted to achieve low quiescent current during skipping cycles. An adaptive zero current detector is presented to reduce dynamic power consumption at light load. The proposed converter is designed with 0.11μm CMOS technology. Simulation results show that the quiescent current is 12nA, and the conversion efficiency achieves 86.2% at 1.5μA load current. The light-load efficiency is 66% higher than the converter without sleep function.