A DC-DC boost converter with variation tolerant MPPT technique and efficient ZCS circuit for thermoelectric energy harvesting applications

Abstract

This paper presents a boost converter with the maximum power point tracking (MPPT) technique for thermoelectric energy harvesting (EH) applications. The technique realizes variation tolerance by adjusting the switching frequency f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SW</sub> of the converter. A finely controlled zero-current switching (ZCS) scheme together with the accurate MPPT technique enhances the overall efficiency (η) of the converter because of an optimal turn-on time generated by a one-shot pulse generator that is proposed. Moreover, the ZCS technique can deal with low and high temperature differences applied to the thermoelectric generator. Experimentally, the converter implemented in a 0.35 um BCDMOS process had a peak of 72% at the input voltage V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">IN</sub> of 500mV while supplying a 5.62V output.