Realization of Linear Voltage Controlled Sinusoid Oscillator/Immittance Functions Using Current Feedback Amplifier
R.K.Nagaria and Rakesh Kumar Singh
This paper presents the design of a CFA- based double integrator loop linear voltage controlled oscillator. The structure exhibits the feature of linear voltage to sinusoid frequency conversion through incorporation of the multiplier elements in each integrator. The control voltage of the multiplier tunes the oscillation frequency (fo) over specific bands preset by the all-grounded RC components. Comparison of the proposed active structure with the basic LC-tank type oscillator identifies the availability of a synthetic-inductor at the CFA-port where a capacitor is shunt connected. Experimental and PSPICE simulation of the VCSO characteristics and the selective resonant response due to the inductor had been obtained. Smooth tuning of fo in the range of 100 KHz to 1 MHz with quadrature oscillations has been verified. The results confirm the workability of the proposed structure.
Keywords: Current feedback amplifier, VCSO, multiplier, port, immittance functions.