A Nanopower Synchronous Charge Extractor IC for Low-Voltage Piezoelectric Energy Harvesting With Residual Charge Inversion

• Published in: IEEE transactions on power electronics Vol. 31; no. 2; pp. 1263 - 1274
• Main Authors: Dini, Michele, Romani, Aldo, Filippi, Matteo, Tartagni, Marco
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.02.2016; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Charge; Converters; Electric charge; Electric currents; Energy efficiency; Energy harvesting; energy harvesting power converter; Energy storage; Extraction; Microelectronics; MOSFET; nano-power; Piezoelectric transducers; Piezoelectricity; power management; Rectifiers; Switches; Synchronous; Transducers; power management; power converter; piezoelectric transducers; Energy harvesting; nanopower
• ISSN: 0885-8993; 1941-0107
• DOI: 10.1109/TPEL.2015.2417352

The paper presents a power converter for piezoelectric energy harvesting implementing a modified version of a synchronous electrical charge extraction with quiescent current as low as 160 nA. The input energy is increased of more than 200% for weak vibrations, by inverting the residual charge left on the capacitance of the transducer after each energy extraction. Moreover, a power management policy, named two-way energy storage, is introduced in order to improve significantly the efficiency of the energy harvesting system in battery-less systems during the startup phase, when the energy storage is fully depleted. The converter behaves as a buck-boost converter, and the measured peak efficiency is 85.3%. The IC has been designed in a 0.32-μm microelectronic technology from STMicroelectronics in an active area of 0.95 mm 2 .