Low power adaptive power management with energy aware interface for wireless sensor nodes powered using piezoelectric energy harvesting

A batteryless power management circuit incorporating an energy aware interface (EAI) for wireless sensor nodes (WSNs) powered by piezoelectric energy harvester (PEH) has been proposed and implemented. Traditional power management usually requires two DC-DC converters, each for maximum power point tracking (MPPT) and voltage regulation functionalities. The proposed circuit requires only one DC-DC converter for both the MPPT and voltage regulation. The EAI also provides a means to voltage regulation. This allows the circuit to have higher efficiency as the energy transfer does not have to go through two stages to reach the load. A PEH connected to the proposed circuit was tested under various vibration conditions. The circuit was found to have end-to-end efficiency of about 66% under most of the test conditions.