A self-starting fully integrated auto-adaptive converter for battery-less thermal energy harvesting

This paper presents a fully integrated DC/DC converter capable of supply a battery-less sensor by extracting the power from thermoelectric generators (TEGs) on a wide temperature gradient range (3K to 12K). The power management unit of the converter enables to directly power a sensor with a 1.2V output regulated voltage for continuous low power sensing operations. It can also manage larger power consumption operations during a short time with a special mode storing energy in the output capacitor at higher voltage. The circuit has been fabricated in UMC180nm process. It starts converting at 250mV input voltage and provides output power up to 1.6mW with a peak efficiency of 70% and a very low silicon area (2.86mm²).