A 60-nA IQ 96.5% Peak Efficiency Buck Converter with Wide Load Range for Internet of Things

This paper presents a 96.5% peak efficiency adaptive ON-time controlled buck converter with 0.001-500 mA load range for internet of things. A novel positive feedback controlled comparator is presented, with its bias current dynamically increased to accelerate the transient responses while maintaining low power consumption. Besides, the power gating scheme and a sub-nA voltage reference is implemented to achieve ultra-low overall quiescent current, leading to an outstanding conversion efficiency. Designed and simulated in a 0.18μm CMOS process, the prototype shows an undershoot voltage of 43 mV and recovery time of 2.8 µs during a load transient from 10 μA to 500 mA, with a total quiescent current of 60 nA. The proposed design shows efficiencies of 95.4%, 96.5% and 91.2% when the load current is 10 μA, 100 μA, and 500 mA, respectively.