Inhee Lee, Wootaek Lim, Alan Teran, Jamie Phillips, Dennis Sylvester, David Blaauw
{"title":"A >78%-Efficient Light Harvester over 100-to-100klux with Reconfigurable PV-Cell Network and MPPT Circuit.","authors":"Inhee Lee, Wootaek Lim, Alan Teran, Jamie Phillips, Dennis Sylvester, David Blaauw","doi":"10.1109/ISSCC.2016.7418061","DOIUrl":null,"url":null,"abstract":"Energy harvesting is an attractive solution to extend system lifetime for internet of everything (IoE) nodes. Ambient light is a common energy source that can be harvested by photovoltaic (PV) cells. However, light intensity varies widely depending on location, ranging from ~10s of lux in dim indoor conditions to ~100klux under direct sunlight. Designing a fully integrated light harvester that spans such a wide range of light intensity with high efficiency is challenging, especially since typically low PV cell voltage requires a high upconversion ratio and PV-cell voltage/current characteristics change significantly with light intensity. Boost DC-DC converters are a typical energy-harvesting solution with high conversion efficiency, but they require a large off-chip inductor and hence cannot be fully integrated, increasing system size [1-3]. Recently, switched-capacitor (SC) DC-DC converters have been actively researched to enable fully-integrated energy harvesting using on-chip capacitors [4-6]. However, their efficiency has typically been limited to the 40-to-55% range at low input power levels (≤1μW) due to conduction/switching losses.","PeriodicalId":72811,"journal":{"name":"Digest of technical papers. IEEE International Solid-State Circuits Conference","volume":"2016 ","pages":"370-371"},"PeriodicalIF":0.0000,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/ISSCC.2016.7418061","citationCount":"27","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Digest of technical papers. IEEE International Solid-State Circuits Conference","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1109/ISSCC.2016.7418061","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 27
Abstract
Energy harvesting is an attractive solution to extend system lifetime for internet of everything (IoE) nodes. Ambient light is a common energy source that can be harvested by photovoltaic (PV) cells. However, light intensity varies widely depending on location, ranging from ~10s of lux in dim indoor conditions to ~100klux under direct sunlight. Designing a fully integrated light harvester that spans such a wide range of light intensity with high efficiency is challenging, especially since typically low PV cell voltage requires a high upconversion ratio and PV-cell voltage/current characteristics change significantly with light intensity. Boost DC-DC converters are a typical energy-harvesting solution with high conversion efficiency, but they require a large off-chip inductor and hence cannot be fully integrated, increasing system size [1-3]. Recently, switched-capacitor (SC) DC-DC converters have been actively researched to enable fully-integrated energy harvesting using on-chip capacitors [4-6]. However, their efficiency has typically been limited to the 40-to-55% range at low input power levels (≤1μW) due to conduction/switching losses.