Design and simulation of a low dropout voltage regulator (LDO) for energy harvesting from footsteps using piezoelectric sensors

Abstract

This study focuses on the design and simulation of a low dropout regulator (LDO) for energy harvesting systems from movements of human footsteps or vehicle using nanofiber piezoelectric sensors. The energy source from piezoelectric sensors exhibits unstable characteristics, including fluctuating alternating voltage, low frequency, and small power output. The LDO circuit was designed using Cadence Virtuoso on 45 nm CMOS technology, incorporating key blocks such as bandgap reference (BGR), error amplifier (EA), buffer, pass FET, and leakage current cancellation. Simulation results demonstrate a stable output voltage of 897.4 mV, a dropout of 200 mV, a power supply rejection ratio of 80.9 dB at low frequencies, and an average power consumption of approximately 48.7 mW at v_in=2 V. Monte Carlo analysis with 1000 samples confirms high stability, with standard deviations of 3.4 V for v_out and 0,7 mW for the total power. These findings highlight the LDO's potential for applications in low-power Internet of Things systems and low-power devices.