Current feedback op-amp based linear voltage-controlled oscillator using analog multipliers and minimum passive components


1 Department of Engineering Education, Faculty of Industrial Education, King Mongkut's Institute of Technology Ladkrabang, Bangkok, 10520, Thailand.

2 D3, Friends Apartment, IP Extension, Delhi, 110092, India.


This paper reports a new realization of linear Voltage-Controlled Oscillator (VCO) using three Current-Feedback Op-Amps (CFOAs), three analog multipliers, and only four passive components. Thus, minimum numbers of passive components are used to devise a canonic sinusoidal oscillator. The circuit provides non-interactive electronic tuning of both the Condition of Oscillation (CO) and the Frequency of Oscillation (FO) via the gains of two di erent analog multipliers. The impedance at output node exhibits low impedance which is easy to directly connect to load without any additional voltage bu er. The proposed circuit has been simulated in SPICE using macro-model of AD844 CFOA ICs and AD633 multiplier ICs.