Single- and multi-source battery-less power management circuits for piezoelectric energy harvesting systems

Innovative multi-source power management circuits which exploit the series-like and parallel-like combinations of multiple power management units are presented. The limitations of traditional topologies are overcome by connecting each piezoelectric converter to a power management unit. In particular, the proposed inverting, buck-boost, parallel-like, power management circuit combines the energy from the storage capacitors of each power management unit in a single storage capacitor exploiting a switch on inductor through trigger circuits. Experimental results show that the proposed inverting buck-boost power stage has an overall efficiency of about 8.5%.