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

• Published in: 2024 IEEE International Symposium on Circuits and Systems (ISCAS) pp. 1 - 5
• Main Authors: Xi, Ruijie, Xue, Chenkang, Li, Jiping, Zhao, Tianting, Li, Mengjiao, Ding, Yong, Li, Wuhua, Qu, Wanyuan
• Format: Conference Proceeding
• Language: English
• Published: IEEE 19.05.2024
• Subjects: adaptive ON-time control; buck; Buck converters; Circuits and systems; CMOS process; Feedback control; Internet of Things; positive feedback control comparator; Power demand; power gating; Prototypes
• ISSN: 2158-1525
• DOI: 10.1109/ISCAS58744.2024.10558536

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.