A self-powered power management circuit for energy harvested by a piezoelectric cantilever

This paper presents development of a self-powered power management circuit for energy harvested by a piezoelectric cantilever. A full-wave rectifier followed by a buck-boost converter running in the discontinuous conduction mode rectifies the AC output, matches the source impedance, and generates a regulated DC output provided the input power is sufficient to charge up the load. A low power microcontroller unit is used for the maximum power point tracking and the output voltage regulation. Experimental results show that the circuit can harvest up to 3.5 mW with a 50 × 31.8 mm
²
piezoelectric cantilever under 0.5 g (rms) base acceleration. Detailed loss analysis is presented for efficiency enhancement in the future.