An Inductor‐Less Flipping‐Capacitor S&P‐SSHC Rectifier for Piezoelectric Energy Harvesting

ABSTRACT This article proposes a Series and Parallel synchronized switching harvesting on capacitor (S&P‐SSHC) rectifier to efficiently extract energy from piezoelectric transducer (PZT). By combining the Series synchronized switching harvesting mode (S‐mode) together with Parallel synchronized switching harvesting mode (P‐mode), the S&P‐SSHC rectifier can achieve an excellent energy harvesting efficiency over a wide range of vibration excitation under a fixed low output voltage. Moreover, the synchronized switch harvesting on capacitor technology utilized in S‐mode with the same flipping caps as using in P‐mode maintains a high‐voltage flipping efficiency ( ), while avoiding the addition of extra components. A switched‐capacitor (SC) DC‐DC converter composed of the reconfigured flipping caps aims to enhance the input independence ability and its limited voltage‐conversion‐ratio (VCR) will not affect harvesting efficiency due to the supplementation of S‐mode. The proposed rectifier circuit is designed and simulated in a 0.18‐ m BCD process. The performance measured by simulation demonstrate that the proposed S&P‐SSHC rectifier can maintain a maximum output power improving rate over full‐bridge rectifier (FOM) of > 6.01 with an open‐circuit peak‐to‐peak voltage of PZT ( ) range from 0.5 to 10 V and a fixed loading voltage of 1.5 V.