Fully integrated boost converter for thermoelectric energy harvesting in 180 nm CMOS

A full integrated boost converter that allows energy extraction from low voltage thermoelectric generators is presented in this paper. The converter uses a 22 nH integrated metal-track inductor without external components and provides a 1.1 V regulated output voltage from 300 mV of input voltage and 39 % of efficiency under normal operation, as experimentally determined. In start-up mode, the proposed architecture utilized a Dickson charge-pump to pre-charge the output capacitor until the control circuit could operate. The presented circuit was simulated and fabricated in 0.18 mu m CMOS technology. Experimental tests were performed on test samples, and the converter efficiency is measured versus output power and also as a function of the input voltage in the range from 0.3 V up to 0.8 V. These results showed that the boost converter works adequately. The core occupies (without pads) a silicon area of about 0.7 mm x 0.9 mm.