Flipping Rectifiers for Piezoelectric Vibration Energy Harvesting

Piezoelectric is a vibration source which can generate energy out of ambient vibrations. Four approaches of energy harvesting circuits in 0.35-µm CMOS process are discussed in the paper, including 1) the full bridge rectifier (FBR), 2) the switch only rectifier (SOR), 3) the parallel-synchronized-switch harvesting-on-inductor (P-SSHI), and 4) the flipping-capacitor rectifier (FCR). Compared to the transferred-power ability of the conventional FBR, the improved factors of SOR, P-SSHI and FCR can reach up to 1.58x, 1.93x and 1.96x at an excitation frequency of 100 Hz, respectively.