A 40 mV Transformer-Reuse Self-Startup Boost Converter With MPPT Control for Thermoelectric Energy Harvesting Jong-Pil Im, Student Member , IEEE, Se-Won Wang ,S t u d e n tM e m b e r ,I E E E

Abstract

This paper present s transformer-based self-starting boost converter architecture with low-power maximum power point tracking (MPPT) control for low-voltage thermoelectric generator applications. T he minimum working voltage of the pro- posed boost converter is 40 mV with oscillation through a positive feedback loop formed by a native MOS and transformer. The oscillation autonomous ly starts up by thermal noise and is charged up to 1.2 V by the oscillation so that the control block can operate. After that, the trans former for start-up is reused as an inductor, and t he normal boost converter mode is enabled for better energy transfer ef ficiency. An improved MPPT sensing method is also proposed to simplify the circuit. The prototype chip is implemented in a 0.13- CMOS process. It operates with an input voltage range of 40 mV to 300 mV and provides a maximum output power of 2.7 mW with a maximum ef ficiency of 61% at an output voltag eo f2V .