Design And Implementation of an Opamp Based Interface Circuit for Improving the Output Power of Frequency Up Conversion Piezoelectric Energy Harvester

Abstract

This paper proposes an interface circuit for a frequency up conversion piezoelectric energy harvester with OPAMP as core controller, which can increase output power by over 400% compared with full bridge circuit. Because of differential amplification characteristics of OPAMP, the failure of traditional logic gates zero-crossing detection circuit in low voltage is overcome. The advantage of frequency up conversion energy harvester is suitable for wide frequency bands, but output waveform is attenuating and oscillating, making circuit design difficult to detect zero-crossing point, causing low power efficiency. Innovations include: (1) Theoretical modeling method of frequency up conversion energy harvester (2) Power management circuit design method suitable for frequency up conversion energy harvester is proposed for the first time. Using OPAMP, control logic is effective in the case of harvester output attenuating and oscillating and current is low. (3) Method about how to choose device parameters.