Switched Capacitors Charge Pump with half-floating Topology for a high-efficient Solar Energy Harvester

This paper describes the design of a fully-integrated high-efficiency power management unit of a solar energy harvester for smart nodes of Internet of Things (IoT) networks. The proposed topology presents a half-floating input to avoid losses charging the top/button plate of the stray capacitors in each clock cycle. Moreover, the proposed harvester is fully integrated on-chip without the need of external components and occupying an area of 0.69 mm2. Simulation results show efficiencies above 80% in the range of 5-25μW output power connected to a 1.42 cm2 solar cell with indoor light conditions (500-1000 lux).