{"title":"Design of a CMOS VCO with two tuning inputs applied for a wideband GFSK-modulated frequency synthesizer","authors":"K. Peng, C. Huang, C. Li, T. Horng, S.F. Lee","doi":"10.1109/RWS.2006.1615190","DOIUrl":null,"url":null,"abstract":"This paper describes the design considerations of a 2.4 GHz CMOS voltage-controlled oscillator (VCO) with two tuning inputs when used in a wideband GFSK-modulated frequency synthesizer based on a two-point delta-sigma modulation (TPDSM) architecture. One tuning input is provided mainly for the fractional-TV frequency synthesis, and the other one is for the direct GFSK modulation. In the VCO design, the tuning sensitivity for GFSK modulation is optimized including the effects of digital-to-analog converter (DAC). In addition, the size of spiral inductor in the LC tank is minimized without the cost of reducing quality (Q) factor. The implemented TPDSM-based GFSK-modulated frequency synthesizer can achieve a maximum data rate of up to 2.5 Mbps with an FSK error less than 1.4% and a phase-locked loop (PLL) settling time less than 110 /spl mu/s. The modulated frequency synthesizer with such good performances has promising application potential in a low-power solution for the enhanced data rate (EDR) Bluetooth transmitters.","PeriodicalId":244560,"journal":{"name":"2006 IEEE Radio and Wireless Symposium","volume":"79 1 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2006-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"5","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"2006 IEEE Radio and Wireless Symposium","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1109/RWS.2006.1615190","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
This paper describes the design considerations of a 2.4 GHz CMOS voltage-controlled oscillator (VCO) with two tuning inputs when used in a wideband GFSK-modulated frequency synthesizer based on a two-point delta-sigma modulation (TPDSM) architecture. One tuning input is provided mainly for the fractional-TV frequency synthesis, and the other one is for the direct GFSK modulation. In the VCO design, the tuning sensitivity for GFSK modulation is optimized including the effects of digital-to-analog converter (DAC). In addition, the size of spiral inductor in the LC tank is minimized without the cost of reducing quality (Q) factor. The implemented TPDSM-based GFSK-modulated frequency synthesizer can achieve a maximum data rate of up to 2.5 Mbps with an FSK error less than 1.4% and a phase-locked loop (PLL) settling time less than 110 /spl mu/s. The modulated frequency synthesizer with such good performances has promising application potential in a low-power solution for the enhanced data rate (EDR) Bluetooth transmitters.