Boost Converter With Dynamic Input Impedance Matching for Energy Harvesting With Multi-Array Thermoelectric Generators

Abstract

This paper presents a built-in input matching technique capable of handling a wide variation of multi-array thermoelectric generator (TEG) impedances ranging two decades, from 10 s to 1000 s of ohms. Maximum power point tracking (MPPT) control for a boost converter (BC) is introduced. The analytical expressions derived offer insight on the manner in which MPPT interacts with a BC to achieve best performance. The BC operates in a discontinuous conduction mode under pulse frequency modulation to minimize power consumption and maximize efficiency for light loads. Losses are minimized by implementing a pseudo-zero current switching control via the PMOS switch on/off time, and the output voltage is set using a global clocked comparator. A prototype was fabricated in 0.5 μm CMOS where efficiency measurements showed a maximum value of 61.15% for an R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TEG</sub> = 33.33 Ω, and quiescent power consumption was 1 μW.