Charge Pump Improvement for Energy Harvesting Applications by Node Pre-Charging

This brief proposes a simple but effective strategy to improve wake-up operation in energy-autonomous systems which exploits Charge Pump (CP) circuits to boost voltage directly from energy harvester generators. By means of few auxiliary diodes and parasitic junctions, the CP is managed to retain the charges in the pumping capacitors when the harvesting power source is not able to feed the system, thereby reducing the rise time and input energy demand during the start-up phase. Simulation results using a 65-nm CMOS technology confirm the potentialities of the proposed strategy and show a reduction of the rise time and the input energy higher than 20% as compared with the traditional topology.