Call for Paper - January 2022 Edition
IJCA solicits original research papers for the January 2022 Edition. Last date of manuscript submission is December 20, 2021. Read More

Design of a Three Stage Ring VCO in 0.18 µm CMOS under PVT Variations

International Journal of Computer Applications
Foundation of Computer Science (FCS), NY, USA
Year of Publication: 2017
N. Ramanjaneyulu, D. Satyanarayana, K. Satya Prasad

N Ramanjaneyulu, D Satyanarayana and Satya K Prasad. Design of a Three Stage Ring VCO in 0.18 µm CMOS under PVT Variations. International Journal of Computer Applications 170(8):35-39, July 2017. BibTeX

	author = {N. Ramanjaneyulu and D. Satyanarayana and K. Satya Prasad},
	title = {Design of a Three Stage Ring VCO in 0.18 µm CMOS under PVT Variations},
	journal = {International Journal of Computer Applications},
	issue_date = {July 2017},
	volume = {170},
	number = {8},
	month = {Jul},
	year = {2017},
	issn = {0975-8887},
	pages = {35-39},
	numpages = {5},
	url = {},
	doi = {10.5120/ijca2017914932},
	publisher = {Foundation of Computer Science (FCS), NY, USA},
	address = {New York, USA}


This paper describes the design of a 3.4 GHz three stage Ring Voltage Controlled Oscillator (VCO). In order to achieve wide tuning range at gega hertz frequencies a three stage ring oscillator based VCO is designed using differential delay cell. The linearity is achieved over a wide-tuning range from 1.5 GHz to 3.8 GHz while maintain the phase noise -116 dBc/Hz at 3.4GHz.The designed VCO is simulated using Cadence 0.18-µm CMOS process and VCO consumes 8.58 mA current and 15.4mW power from a 1.8V power supply. The designed VCO is generating a frequency of 3.4 GHz over a temperature range from 0o C to 65o C. The VCO has been found to work for all Process (Typical, Slow and Fast corners), Voltage and Temperature (PVT) conditions.


  1. The High Definition Multimedia Interface Specification version 1.4a,
  2. Ramanjaneyulu N., Satyanarayana D., Satya Prasad K. (2017) Design of a 3.4 GHz Wide-Tuning-Range VCO in 0.18 μm CMOS. Part of the Lecture Notes in Networks and Systems book series, vol 5,pp 227-234. Springer, Singapore.
  3. Razavi. B, Lee. K and Yan. Y “Design of high speed, low power frequency dividers and phase locked loops in deep submicron CMOS” IEEE J. Solid-State Circuits, vol. 30, no.2.pp.101–109, 1995.
  4. Ping-Hsuan Hsieh, jay Maxey, and Chih-Kong ken yang “Minimizing the supply sensitivity of a CMOS ring oscillator through jointly biasing the supply and control voltages”, IEEE J. Solid-State Circuits, vol. 44, no.9,pp-2488–2495,2009.
  5. Jun-Chau Chien, and Liang-Hung Lu “Design of wide-tuning-range millimeter-wave CMOS VCO with a standing-wave architecture,” IEEE J. Solid-State Circuits, vol. 42, no. 9, pp. 1942–1952, Sep. 2007.
  6. Young-Jin Moon, Yong-Seong Roh, Chan-Young Jeong, and Changsik Yoo , “A 4.39–5.26 GHz LC-tank CMOS voltage-controlled oscillator with small VCO-gain variation,” IEEE Microw. Wireless Compon. Lett., vol. 19, no. 8, pp. 524–526, Aug. 2009.
  7. Jian-An Hou and Yeong-Her Wang “A 5 GHz differential colpitts CMOS VCO using the bottom PMOS cross-coupled current source,” IEEE Microw.Wireless Component Lett., vol. 19, no. 6, pp. 401–403, Jun. 2009.
  8. José Luis González, Franck Badets, Baudouin Martineau, and Didier Belot “A 56-GHz LC-tank VCO with 17% tuning range in 65-nm bulk CMOS for wireless HDMI,” IEEE Trans. Microw. Theory Techn., vol. 58, no. 5, pp. 1359–1366, May 2010.
  9. Meng-Ting Hsu and Po-Hung Chen, “5G Hz low power CMOS LC VCO for IEEE 802.11a application,” in Proc. Asia-Pacific Microw. Conf., Dec. 2011, pp. 263–266
  10. Zuow-Zun Chen and Tai-Cheng Lee The design and analysis of dual-delay-path ring oscillators” IEEE Trans Circuits Syat.I,vol.58,no.3,pp. 470-478 ,march 2011
  11. Pei-Kang Tsai and Tzuen-His Huang, “Integration of current-reused VCO and frequency tripler for 24-GHz low-power phase-locked loop applications,” IEEE Trans. Circuits Syst. II, Exp. Briefs, vol. 59, no. 4, pp. 199–203, Apr. 2012.
  12. Qiyang Wu, Salma Elabd, Tony K. Quach, Aji Mattamana, Steve R. Dooley, Jamin McCue, Pompei L. Orlando, Gregory L. Creech and Waleed Khalil., “A–189 dBc/Hz FOMT wide tuning range Ka-band VCO using tunable negative capacitance and inductance redistribution,” in Proc. IEEE Radio Freq. Integr. Circuits (RFIC) Symp., Jun. 2013, pp. 199–202.
  13. Heein Yoon, Yongsun Lee, Jae Joon Kim, and Jaehyouk Choi, “A wideband dual-mode LC-VCO with a switchable gate-biased active core,” IEEE Trans. Circuits Syst. II, Exp. Briefs, vol. 61, no. 5, pp. 289–293, May 2014.


Delay cell, Ring oscillator, Voltage Controlled Oscillator, Communication systems.