50 mV-Input Batteryless Boost Converter for Thermal Energy Harvesting

A fully electrical startup boost converter for thermal energy harvesting is presented in this paper. The converter is implemented in a 65-nm bulk CMOS technology. With the proposed 3-stage stepping-up architecture, the minimum input voltage for startup is as low as 50 mV while the input voltage required for sustained power conversion is 30 mV. Due to the use of a zero-current-switching (ZCS) converter as the last stage and an automatic shutdown mechanism for the auxiliary converter, conversion efficiency up to 73% is achieved. By incorporating the boost converter and a thermoelectric generator (TEG), a miniaturized module is demonstrated for energy harvesting applications.