An ultra-compact differentially tuned 6-GHz CMOS LC-VCO with dynamic common-mode feedback

作者：Soltanian Babak^*; Ainspan Herschel; Rhee Woogeun; Friedman Daniel; Kinget Peter R

来源：IEEE Journal of Solid-State Circuits, 2007, 42(8): 1635-1641.

DOI：10.1109/JSSC.2007.903068

• CMOS integrated circuits
• common-mode feedback
• compact VCO
• differential tuning
• LC-VCO
• oscillators
• phase noise
• radio frequency
• voltage-controlled oscillators

A fully integrated 0.024 mm(2) differentially tuned 6-GHz LC-VCO for 6+Gb/s high-speed serial (HSS) links in 90-nm bulk CMOS is presented. It is smaller than any LC-VCO reported to date at this frequency. Its size is comparable with ring oscillators but it has significantly better phase noise. A circuit technique is introduced to dynamically set the common-mode (CM) voltage of the differential varactor control signals equal to the VCO's CM. Compared to other commonly used techniques such as replica biasing, this technique does not dissipate any extra power and it accurately tracks the output common-mode voltage of the VCO during the oscillations. Using a differential control a very wide tuning range from 4.5 GHz to 7.1 GHz (45%) is achieved. The VCO has a measured phase noise of -117.7 dBc/Hz at a 3-MHz offset from a 5.63-GHz carrier while dissipating 14 mW from a 1.6-V supply.

• 出版日期2007-8
• 单位清华大学