A Full-Wave Rectifier With Integrated Peak Selection for Multiple Electrode Piezoelectric Energy Harvesters

Piezoelectric transducers are a viable way of harvesting vibrational energy for low power embedded systems such as wireless sensors. A proposed disk-shaped piezoelectric transducer with several electrodes enables increased energy harvesting from multiple mechanical resonances. To rectify the low-frequency AC voltage from harvested vibrational energy, a full-wave rectifier has been fabricated in 0.35 mum CMOS. Integrated peak selection circuitry allows input signals with 90deg relative phase shift from the multiple-electrode piezoelectric transducer to be rectified with reduced output ripple. The rectifier has a measured power efficiency of 98.3% while delivering 90 muW and occupying an area of 0.007 mm² . This high efficiency further enables energy harvesters to power wireless devices for extended durations.