CMOS-Compatible Linear VCO Using a Single CFOA and Grounded Capacitors

D. K. Srivastava¹, V. K. Singh² and R. Senani^3,

¹Department of Electronics and Communication Engineering, SR Institute of Management and Technology, Lucknow, India

²Department of Electronics Engineering, Institute of Engineering and Technology, Sitapur Road, Aliganj, Lucknow, India

³Division of Electronics and Communication Engineering, Netaji Subhas Institute of Technology, Sector 3, Dwarka, New Delhi, India

Cite this paper

D. K. Srivastava, V. K. Singh and R. Senani. CMOS-Compatible Linear VCO Using a Single CFOA and Grounded Capacitors. American Journal of Electrical and Electronic Engineering. 2017; 5(6):202-206. doi: 10.12691/AJEEE-5-6-2

Abstract

A simple CMOS-compatible linear voltage controlled oscillator (VCO) has been presented which employs a single CFOA, four MOSFETs and three grounded capacitors as preferred for IC implementation. In the proposed circuit, variable frequency oscillations are obtained by simultaneous variation of two voltage-controlled-resistors in the circuit which appear in the expression for oscillation frequency in the product form but appear as a ratio in the condition of oscillation (which therefore, remains unaffected). The workability of the proposed VCO has been confirmed by SPICE simulations using an exemplary CMOS CFOA and CMOS VCRs both implementable in 0.18µm CMOS technology.

Keywords

sinusoidal oscillators, current feedback operational amplifiers, voltage controlled oscillators, voltage controlled resistance

Copyright

This work is licensed under a Creative Commons Attribution 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/

References

[1]	Y. Tsividis, M. Banu, J. Khoury, “Continuous-time MOSFET-C filters in VLSI” IEEE Journal of Solid-State Circuits, 21, 15-30, 1986.
[2]	D. R. Bhaskar, R. Senani, “New current-conveyor-based single-resistance-controlled/voltage-controlled oscillator employing grounded capacitors” Electronics Letters, 29, 612-614,1993 .
[3]	S. Celma, PA Martinez, A. Carlosena, “Current feedback amplifiers based sinusoidal oscillators” IEEE Trans Circuits and Syst-I: Fundamental Theory and Applications, 41, 906-908, 1994.
[4]	R. Senani, V.K. Singh, “Novel single resistance controlled oscillator configuration using current feedback amplifiers” IEEE Trans Circuits and Syst-I: Fundamental Theory and Applications; 43, 698-700, 1996.
[5]	R. Senani, V.K. Singh, “Comment: Synthesis of canonic single resistance controlled oscillators using single current feedback amplifier” IEE Proc Circuits Device; 143(1), 71-72, 1996.
[6]	M.T. Abuelma′atti, S.M. Al-Shahrani, “A Novel low-component-count single-element-controlled sinusoidal oscillator using the CFOA pole”, Int J Electron, 80(6),747-752,1996.
[7]	M.T. Abuelma′atti, S.M. Al-Shahrani, “New CFOA-based grounded-capacitor single element controlled sinusoidal oscillator”, Active and Passive Electronic Components, 20,119-124, 1997.
[8]	R. Senani, “Realization of a class of analog signal processing/signal generation circuits: novel configurations using current feedback op-amps”, Frequenz, 52, 196-206, 1998.
[9]	D. R. Bhaskar, M. P. Tripathi, “Realization of novel linear sinusoidal VCOs”, Analog Integrated Circuits and Signal Processing, 24, 263-267, 2000.
[10]	S.A. Mahmoud, A.M. Soliman, “Novel MOS-C oscillators using the current feedback op-amp”, Int J Electron, 87, 269-280, 2000.
[11]	V.K. Singh, R.K. Sharma, A.K. Singh, D.R. Bhaskar, R. Senani, “Two new canonic single-CFOA oscillators with single resistor controls”, IEEE Trans. on Circuits and Systems-II, Express Briefs, 52, 860-865, 2000.
[12]	A.M. Soliman, “Current feedback operational amplifier based oscillators”, Analog Integrated Circuits and Signal Processing, 23, 45-55, 2000.
[13]	U. Cam, “A Novel single-resistance-controlled sinusoidal oscillator employing single operational trans-resistance amplifier”, Analog Integrated Circuits and Signal Processing, 32, 183-186, 2002.
[14]	A. Toker, O. Cicekoglu, H. Kuntman, “On the oscillator implementations using a single current feedback op-amp”, Computers and Electrical Engineering, 28, 375-389, 2002.
[15]	D. R. Bhaskar, R. Senani, “New CFOA-based single-element-controlled sinusoidal oscillators”, IEEE Transactions on Instrumentation and Measurement, 55, 2014-2021, 2006.
[16]	H.P. Chen, K.H. Wu, “Voltage-mode DDCC-based multifunction filters”, Journal of Circuits, Systems and Computers, 16, 93-104, 2007.
[17]	S.M. Al-Shahrani, “CMOS wideband auto-tuning phase shifter circuit”, Electronics Letters, 43, 804-805, 2007.
[18]	S.S. Gupta, D.R. Bhaskar, R. Senani, “New voltage controlled oscillators using CFOAs”, Int J Electron Commun (AEÜ), 63, 209- 217, 2009.
[19]	R. Senani, D.R. Bhaskar, S.S.Gupta, V.K.Singh, “A configuration for realizing floating, linear, voltage-controlled resistance, inductance and FDNC Elements”, International Journal of Circuit Theory and Applications, 37, 709-719, 2009.
[20]	D.R. Bhaskar, R. Senani, A.K. Singh, S.S. Gupta, “Two simple analog multipliers based linear vco’s using a single current feedback op-amp”, Circuits and Systems, 1, 1-4, 2010.
[21]	D.R. Bhaskar, Raj Senani, A.K. Singh, “Linear sinusoidal vco’s: new configurations using current-feedback-op-amps”, Int. J Elec, 97, 263-272, 2009.
[22]	S.S. Gupta, D.R. Bhaskar, R. Senani, A.K. Singh, “Synthesis of Linear vco’s: The state-variable approach” Journal of Circuits, Systems and Computers, 20, 587-606, 2011.
[23]	S.S. Gupta, D.R. Bhaskar, R. Senani, “Synthesis of new single CFOA-based vco’s incorporating the voltage summing property of analog multipliers”, ISRN Electronics, 1-8, 2012.
[24]	R. Senani, D.R. Bhaskar, A.K. Singh, V.K. Singh, “Current feedback operational amplifiers and their applications”. Springer Science + Business Media, New York 2013, Chapter 5, 131-176.
[25]	R. Senani, D.R. Bhaskar, V.K. Singh R.K. Sharma, “Sinusoidal oscillators and waveform generators using modern electronic circuit building blocks”. Springer International Publishing, Switzerland 2016; Chapter 5: 213-264.
[26]	R.W. Newcomb, “Active integrated circuit synthesis”, Prentice-Hall Electrical Engineering Series, 1-292, 1968.
[27]	M. Bhushan, R. Newcomb, “Grounding of capacitors in integrated circuits”, Electronics Letters, 3, 148-149, 1967.
[28]	S.S. Gupta, R. Senani, “Realization of current-mode SRCO’s using all grounded passive elements”, Frequenz, 57, 26-37, 2003.