{"title":"A novel continuous-time common-mode feedback for low-voltage switched-OPAMP","authors":"M. Ali-Bakhshian, K. Sadeghi","doi":"10.1145/1013235.1013308","DOIUrl":null,"url":null,"abstract":"A novel rail-to-rail and fast continuous-time common-mode feedback (CMFB) strategy is presented for low-voltage switched-opamp (SO) circuits. The threshold voltage change due to bulk signal is used to measure the output voltage. To satisfy speed requirements, averaging common-mode (CM) level and amplifying error signal are realized in a single block. Finally, the measured CM level is controlled by applying an error-voltage dependent current to the output nodes. As a design example, a modified low-voltage switched-opamp in a cascade 2-1 delta-sigma modulator adopting the proposed technique is presented. SPICE simulation using a 0.18 /spl mu/m technology and V/sub DD/=0.9 V is provided which confirms the expected accuracy and speed of the CMFB circuitry.","PeriodicalId":120002,"journal":{"name":"Proceedings of the 2004 International Symposium on Low Power Electronics and Design (IEEE Cat. No.04TH8758)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2004-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"5","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Proceedings of the 2004 International Symposium on Low Power Electronics and Design (IEEE Cat. No.04TH8758)","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1145/1013235.1013308","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 5
Abstract
A novel rail-to-rail and fast continuous-time common-mode feedback (CMFB) strategy is presented for low-voltage switched-opamp (SO) circuits. The threshold voltage change due to bulk signal is used to measure the output voltage. To satisfy speed requirements, averaging common-mode (CM) level and amplifying error signal are realized in a single block. Finally, the measured CM level is controlled by applying an error-voltage dependent current to the output nodes. As a design example, a modified low-voltage switched-opamp in a cascade 2-1 delta-sigma modulator adopting the proposed technique is presented. SPICE simulation using a 0.18 /spl mu/m technology and V/sub DD/=0.9 V is provided which confirms the expected accuracy and speed of the CMFB circuitry.