A compact multi-input thermoelectric energy harvesting system with 58.5% power conversion efficiency and 32.4-mW output power capability

A multiple-input thermoelectric energy harvesting system implemented in a 0.18-μm CMOS technology is proposed to reduce hardware complexity and achieve time efficiency. By combining inductor-sharing and bidirectional-converter techniques, the harvesting-stage and the regulating-stage circuits can be merged into a single-stage power converter. With the proposed duty cycle based impedance adjustment technique for the maximum power extraction, the proposed multi-input thermoelectric energy harvesting system can ensure optimal power transfer from each thermoelectric energy source without sacrificing power conversion efficiency (PCE) and output power capability. The peak PCE achieves at 58.5%, the maximum end-to-end output power is 2.43 mW, and the maximum output power capability can achieve above 32.4 mW while the storage capacitor is fully charged.