A 3.5mV Input, 82% Peak Efficiency Boost Converter with Loss-Optimized MPPT and 50mV Integrated Cold-Start for Thermoelectric Energy Harvesting

This paper presents a fully-autonomous singleinductor boost converter architecture suitable for thermal energy harvesting from human body heat using thermoelectric generators (TEG). A loss-optimized maximum power point tracking (MPPT) scheme improves the end-to-end power efficiency at low voltages from the TEG and enables the converter to operate at an input voltage as low as 3.5 mV. The boost converter achieves above 75% efficiency across a matched input voltage range of 15 mV to 100 mV with a peak efficiency of 82%. The proposed converter is implemented in a 0.18 μm CMOS technology and can self-start at 50 mV using an on-chip cold-start mechanism.