Piezoelectric Energy Harvesting at Circuit Resonance with Active Inductor (CRAI)

Background: Most of the proposed interface circuits use bulky inductors to enhance the key performance parameter, i.e., power transfer efficiency. This sets constraints on designing power conditioning circuitry for constrained IoT applications. Objective: To replace the bulky physical inductor with area-optimized components suitable for integrated circuit realization with reduced silicon footprint for constrained applications like Internet-of- Things (IoT). Methods: This paper presents the implementation of Circuit Resonance with Active Inductor (CRAI) technique based interface circuit design to deliver the maximum power generated from the Piezoelectric Energy Harvesting (PEH) source to the load. Results: Compared to the conventional FWBR technique, the proposed CRAI technique improves ≈2X power delivered to the load. Conclusion: The proposed work presents an inductor-less interface circuit for PEH. An active inductor (gyrator) is used to induce ‘IP’ rejection at the PEH circuit resonant frequency to enhance the performance parameters. Since the proposed technique is based on active inductor, it can be easily fabricated in small Integrated Circuit (IC) packages, allowing integration with state-of-the-art constrained IoT applications. CRAI technique based on the rejection of ‘IP’ at the resonance using active inductor as first reported here. The proposed concept is non-adiabatic, but it could be used for constrained self-powered autonomous IoT applications and could be important in guiding the design of new interface circuits for PEH.