A Versatile Quadrature Oscillator and Universal Biquad Filter Using Dual-Output Current Controlled Current Differencing Transconductance Amplifier

Abstract

In this article, a novel circuit, which can function both as quadrature oscillator and as universal biquad filter (lowpass, highpass, bandpass) are introduced. Working as quadrature oscillator, the oscillation condition and oscillation frequency can be adjusted independently by the input bias current. Functioning as universal biquad filter, the quality factor and cutoff frequency can be tuned orthogonally via the input bias current. The proposed circuit can work as either quadrature oscillator or biquad filter without changing circuit topology. The proposed circuit provides output signal both current-mode and voltage-mode simultaneously. The circuit description is very simple, consisting of merely one dual output current controlled current differencing transconductance amplifier (DO-CCCDTA) and 2 grounded capacitors. Without any external resistors and using only grounded element, this circuit is then suitable for IC architecture. The PSPICE simulation results are depicted. The given results agree well with the theoretical anticipations. The power consumption is approximately 1.89 mW at plusmn2.5 V supply voltages