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 μm 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 × 0.9 mm.