Journal Article

Start-up circuit for low-power indoor light energy harvesting applications

Carvalho, C., Paulino, N.

2013

Overview

A start-up circuit, used in a micro-power indoor light energy harvesting system, is described. This start-up circuit achieves two goals: first, to produce a reset signal, power-on-reset (POR), for the energy harvesting system, and secondly, to temporarily shunt the output of the photovoltaic (PV) cells, to the output node of the system, which is connected to a capacitor. This capacitor is charged to a suitable value, so that a voltage step-up converter starts operating, thus increasing the output voltage to a larger value than the one provided by the PV cells. A prototype of the circuit was manufactured in a 130 nm CMOS technology, occupying an area of only 0.019 mm2. Experimental results demonstrate the correct operation of the circuit, being able to correctly start-up the system, even when having an input as low as 390 mV using, in this case, an estimated energy of only 5.3 pJ to produce the start-up.

• Publisher: The Institution of Engineering and Technology,Institution of Engineering and Technology
• Subject: Applied sciences / capacitor / capacitors / CMOS integrated circuits / CMOS technology / Energy / energy harvesting / Exact sciences and technology / General equipment and techniques / Instruments, apparatus, components and techniques common to several branches of physics and astronomy / low‐power indoor light energy harvesting / micropower indoor light energy harvesting system / Natural energy / photovoltaic cells / Photovoltaic conversion / Physics / power convertors / Power electronics, energy conversion and sustainability / power‐on‐reset / PV cells / solar cells / Solar cells. Photoelectrochemical cells / Solar energy / start‐up circuit / Transducers / voltage 390 mV / voltage step‐up converter