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

Authors: RIDVAN UMAZ

Abstract: A two-stage power converter with maximum power extraction for energy harvesting is presented. The power converter consists of two stages; a maximum power extraction stage (i.e. first stage) and a regulation stage (i.e. second stage). The first stage consists of a number of charge pumps connected in parallel to extract power from the energy source while the second stage steps up low input voltage level to a usable level for a load. Proposed converter operates as low as 0.3 V and the output up-converts to 3.3 V. The proposed converter is aimed to extract maximum power from either low-power energy sources or high-power energy sources without increasing the complexity of the converter. Measured results indicate 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 pump one. The end-to-end efficiency is enhanced by 1.67$X$ as compared to the single charge pump implementation.

Keywords: Power converter, boost converter, charge pump, energy harvesting, maximum power

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