{"title":"Imager with Dynamic LSB Adaptation and Ratiometric Readout for Low-Bit Depth 5-μW Peak Power in Purely-Harvested Systems","authors":"K. Ahmed, Longyang Lin, P. Salamani, M. Alioto","doi":"10.1109/vlsitechnologyandcir46769.2022.9830147","DOIUrl":null,"url":null,"abstract":"An imager with μW peak power is introduced for purely-harvested operation. The LSB is dynamically adapted to the light intensity of the scene for aggressive bit depth downscaling, avoiding traditional dynamic range over-margining across practical light intensities under fixed LSB. Ratiometric readout of pixel current cancels threshold voltage mismatch. A 256×256-pixel 180-nm imager shows 5-μW power at 1 fps and 4 bits, while keeping ImageNet classification accuracy drop to percentage points under 75-dB ambient light range, across original and brightness-adjusted images.","PeriodicalId":332454,"journal":{"name":"2022 IEEE Symposium on VLSI Technology and Circuits (VLSI Technology and Circuits)","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2022-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"2022 IEEE Symposium on VLSI Technology and Circuits (VLSI Technology and Circuits)","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1109/vlsitechnologyandcir46769.2022.9830147","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 2
Abstract
An imager with μW peak power is introduced for purely-harvested operation. The LSB is dynamically adapted to the light intensity of the scene for aggressive bit depth downscaling, avoiding traditional dynamic range over-margining across practical light intensities under fixed LSB. Ratiometric readout of pixel current cancels threshold voltage mismatch. A 256×256-pixel 180-nm imager shows 5-μW power at 1 fps and 4 bits, while keeping ImageNet classification accuracy drop to percentage points under 75-dB ambient light range, across original and brightness-adjusted images.