A Miniature and High-efficiency Interface Circuit Based on SSHC for Piezoelectric Energy Harvesting

This paper proposes a miniature and high efficiency interface circuit based on synchronous switch harvesting on capacitors (SSHC) for piezoelectric energy harvesting (PEH). The interface circuit consists of the SSHC circuit and a two-stage synchronous rectifier composed of a negative voltage converter (NYC) and an active diode (AD). The SSHC circuit aims to improve the power extraction capability of the rectifier. The two-stage synchronous rectifier aims to improve the rectification efficiency. The proposed interface circuit is designed in SMIC 0.35 mu m CMOS process. The simulation results show that when the open circuit voltage of the rectifier is 3.4V, the voltage flipping efficiency is as high as 83.6%. The circuit proposed achieves a 2.97x performance improvement compared with a full-bridge rectifier and the peak power converting efficiency is up to 91.5%. The volume of the peripheral components used in the circuit proposed is only 0.6mm(3), which is much smaller than the traditional synchronous switch harvesting on inductor (SSW) interface circuit.