Table of Contents
ISRN Electronics
Volume 2012, Article ID 463680, 8 pages
Research Article

Synthesis of New Single CFOA-Based VCOs Incorporating the Voltage Summing Property of Analog Multipliers

1Department of Industrial Policy and Promotion, Ministry of Commerce and Industry, Government of India, Udyog Bhawan, New Delhi 110011, India
2Department of Electronics and Communication Engineering, Faculty of Engineering and Technology, Jamia Millia Islamia, New Delhi 110025, India
3Division of Electronics and Communication Engineering, Netaji Subhas Institute of Technology, Sector 3, Dwarka, New Delhi 110078, India

Received 26 May 2012; Accepted 4 July 2012

Academic Editors: S. Gift, D. Rossi, and E. Tlelo-Cuautle

Copyright © 2012 S. S. Gupta et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Recently, current feedback operational amplifier (CFOA) and analog multiplier-(AM-) based-voltage controlled oscillators (VCOs) have been published in the literature which require 2 CFOAs and 2 AMs for linear tuning law between control voltage and frequency of oscillation. In this paper, a family of eight new voltage-controlled oscillators (VCOs), with linear tuning laws, employing only a single CFOA in conjunction with two analog multipliers (AMs), has been derived through a systematic state-variable methodology. This has been made possible by exploiting the voltage summing property of the multiplier chosen which has never been done in the literature earlier. The workability of the presented VCOs has been verified by experimental results based on AD844 type CFOAs and AD534 type AMs, and the advantages of new circuits over the previously known CFOA-AM-based VCOs have been highlighted.