A Fast Sampling Open-circuit Voltage Algorithm for Piezoelectric Energy Harvesting

This paper presents a fast sampling open-circuit voltage algorithm for piezoelectric energy harvesting, which directly samples the output of the piezoelectric transducer and limits the sampling time to one piezoelectric vibration period. Therefore, it greatly reduces the power loss caused by the open-circuit sampling and improves the efficiency of the piezoelectric energy harvesting. The proposed circuit is implemented in 0.18 µm standard CMOS process, and the core circuit area is 670×536 µm2. The circuit can sample the open-circuit voltage in less than one piezoelectric vibration cycle and output the maximum power point voltage, and the power loss rate is less than 0.79%.