A 60 µW low-power low-voltage power management unit for a self-powered system based on low-cost piezoelectric powering generators

This paper presents the architecture of a novel implementation of an integrated self-powered system based on piezoelectric vibrations in a 0.13 mum technology. The electromechanical transduction is performed by using a low-cost commercial piezoelectric, working at low frequencies, with voltages up to 2.5 V. The system is conceived as a System In a Package (SiP). The full integrated system is adapted to work with low-voltage and low-power conditions. The full custom power management circuit is used to charge a storage capacitor (super capacitor), from which the stored energy will be used to power, by controlled cycles of discharge operation of a very low power wireless sensor node that could be used in heavy machinery monitoring. Each circuitry block of the power management circuitry is presented and discussed. The simulated studies are fully validated by experimental tests. The experimental consumption of the power management unit is 67 muW, approach to the theoretical expected value of 60 muW.