%0 Journal Article
%T Electronically Tunable Sinusoidal Oscillator Circuit
%A Sudhanshu Maheshwari
%A Rishabh Verma
%J Active and Passive Electronic Components
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/719376
%X This paper presents a novel electronically tunable third-order sinusoidal oscillator synthesized from a simple topology, employing current-mode blocks. The circuit is realized using the active element: Current Controlled Conveyors (CCCIIs) and grounded passive components. The new circuit enjoys the advantages of noninteractive electronically tunable frequency of oscillation, use of grounded passive components, and the simultaneous availability of three sinusoidal voltage outputs. Bias current generation scheme is given for the active elements used. The circuit exhibits good high frequency performance. Nonideal and parasitic study has also been carried out. Wide range frequency tuning is shown with the bias current. The proposed theory is verified through extensive PSPICE simulations using 0.25£¿¦̀m CMOS process parameters. 1. Introduction The sinusoidal oscillators constitute an important building block which finds numerous applications in analogue signal processing. £¿This electronic function provides standard test and carrier signals for communication and instrumentation circuits and also acts as the starting signal for generation of several other types of test signals. Similarly, the multiphase oscillators also find interesting applications in communication and instrumentation systems. For these highly precise processes, third-order sinusoidal oscillators are best suited because they enjoy lower harmonic distortions as compared to the second-order sinusoidal oscillators [1]. When the repertoire of technical literature is surveyed, many oscillator circuits are available based on one or the other type of active devices [2¨C4], but the third-order oscillators are not available in profusion. The third-order oscillators were first proposed in [5] using operational transconductance amplifiers (OTAs), but the dynamic range of the circuits based on OTAs is very limited [6]. Also, the frequency of oscillation cannot be controlled without affecting the condition of oscillation. The reported third-order oscillator in [7] provided four quadrature current outputs, all at high impedance, which makes it suitable for current-mode analogue signal processing. Two current-mode third-order sinusoidal oscillators are proposed in [8] which require three OTAs and three grounded capacitances. In the second oscillator circuit, the frequency of oscillation cannot be controlled without affecting the condition of oscillation. Also, for a large variation in the bias current, it gives a relatively less variation in the frequency of oscillation. The circuit proposed in [9] has limited
%U http://www.hindawi.com/journals/apec/2012/719376/