A Dual-Frequency Dual-Input-Dual-Output Interface for Thermoelectric Energy Harvesting and Recycling With 82.9% Efficiency

A single-inductor dual-input dual-output interface based on a Buck-Boost converter is proposed for thermoelectric energy harvesting. Triple operation modes involving energy harvesting and recycling make the interface qualified for a wide range of load power from zero to a few milliwatts. A dual-frequency operation allows high efficiencies for all the modes. Parameters optimization also reduces the total loss within the system. A novel zero-current switching technique is utilized to realize an accurate switching with little overhead. The proposed interface is implemented in a 0.13-µm CMOS process. The input voltage ranges from 30 mV to 440 mV. The peak efficiency for energy harvesting is 82.9% for 791 µW available power. Higher than 70% efficiency is achieved over the available power range of 26 µW to 914 µW. The power consumption of the control circuits is 308 nW.