A High Efficiency Self-Powered Rectifier for Piezoelectric Energy Harvesting Systems

A high efficiency self-powered rectifier for piezoelectric (PE) energy harvesting systems is proposed. The rectifier in this paper increases the harvested power from the PE transducer by using two switches to reset the transducer capacitor when appropriate. The control circuit for the proposed rectifier is simple and does not require an external supply voltage. Furthermore, the passive diode of the conventional full-bridge (FB) rectifier is replaced by active diode to reduce the voltage drop along the conduction path and thereby increases the power extraction and conversion capability. Based on SMIC 0.18 mu m standard CMOS technology, the simulation results show the voltage conversion efficiency can reach up to 98.9% and the maximum power efficiency is 93.1% when the input current source I-P = 100 mu A in parallel with internal capacitor C-P = 25 nF and internal resistor R-P = 1 M Omega.