DC DC Boost Converter for Thermoelectric Energy Harvesting

Boost converters are used to boost the low d.c. voltage to high d.c. voltage. This boosted d.c. voltage can be used for powering low powered devices, such as implanted medical devices. In this paper a digital boost converter which is low powered is presented for thermoelectric energy harvesting. A pulse stretcher circuit has been proposed to decrease the dead time of the discontinuous mode (DCM) boost converter. The pulse stretcher circuit optimizes the switching time of nMOSFET and pMOSFET giving up to 20 % more conversion efficiency (ratio of the output d.c. voltage to input d.c. voltage) than that of the existing boost convertor circuit. The proposed boost converter produces a stable 1 V d.c. output voltage with 10 μA load current from input of 50 mV.