A two-stage power converter architecture with maximum power extraction for low-power energy sources

Abstract

A two-stage power converter with maximum power extraction for energy harvesting is presented. The powerconverter consists of two stages; a maximum power extraction stage (i.e. first stage) and a regulation stage (i.e. secondstage). The first stage consists of a number of charge pumps connected in parallel to extract power from the energy sourcewhile the second stage steps up low input voltage level to a usable level for a load. Proposed converter operates as low as0.3 V and the output up-converts to 3.3 V. The proposed converter is aimed to extract maximum power from either lowpower energy sources or high-power energy sources without increasing the complexity of the converter. Measured resultsindicate that the tracking efficiency is enhanced by 117%–123% over a single charge pump in the first stage converter.Proposed power converter provides 66.7% more power extracted from the energy source than the single charge pumpone. The end-to-end efficiency is enhanced by 1.67X as compared to the single charge pump implementation.