An ultra-low-voltage self-powered energy harvesting rectifier with digital switch control

Abstract

This paper presents an ultra-low-voltage high-efficiency interface circuit for energy harvesting, which features self-powered design and digital switch control. The proposed rectifier includes bridge rectifier and active diode. The former introduces self-driven switches and ultra-low voltage divider to reduce the voltage drop for wide output voltage swing. The latter adopts a common-gate comparator as switch control block to output a nearly digital signal, thereby improving dynamic response and antinoise ability. The entire circuit exhibits good conversion efficiency and stability. Its minimum input voltage is down to 225mV. The maximum voltage efficiency reaches to 96.3%, supplying the output current of 29μA and the output power of 15.43μW. The maximum power efficiency is 96.5%, providing the output current of over 16.1μA and the output power of 5.19μW. The whole circuit consumes the power loss of 1.42μW.