A 0.9- to 8-GHz VCO With a Differential Active Inductor for Multistandard Wireline SerDes

• Published in: IEEE transactions on circuits and systems. II, Express briefs Vol. 61; no. 8; pp. 559 - 563
• Main Authors: Kuo-Hsing Cheng, Cheng-Liang Hung, Alex Gong, Cihun-Siyong, Jen-Chieh Liu, Bo-Qian Jiang, Shi-Yang Sun
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.08.2014; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Active inductors; Circuits; CMOS; Design engineering; Frequency measurement; Inductors; Phase locked loops; Phase noise; Power consumption; Q-factor; Redesign; SERD; Tuning; Voltage-controlled oscillators; wireline SerDes interfaces; wideband; voltage-controlled oscillator (VCO); Differential active inductor
• ISSN: 1549-7747; 1558-3791
• DOI: 10.1109/TCSII.2014.2327451

This study demonstrates a wide frequency tuning range LC voltage-controlled oscillator (LC-VCO) with an active inductor in a 90-nm CMOS process. As the proposed LC-VCO is intended to be extremely flexible without redesign for several new-generation SerDes interfaces, a wide operating frequency makes the phase-locked loop (PLL) applicable to the multistandards. To demonstrate a highly competitive design, a quality (Q) factor enhancement technique has been also demonstrated to reduce the loss from the active inductor, leading to an appropriate phase noise over the entire tuning range. At a supply of 1.2 V, the fabricated LC-VCO provides a frequency tuning range of 0.9-8 GHz (160%) with power consumption of 3.2-19.1 mW. The measured phase noise is from -105 to -118 dBc/Hz at a 1-MHz offset. Realized in a fully integrated PLL chip, it occupies an active area of 0.08 × 0.16 mm 2 .