DVCCs based high input impedance voltage-mode three-inputs universal biquad

In this paper, a voltage-mode universal biquadratic filter with high input impedance is presented. The proposed circuit has three input terminals and uses three differential voltage current conveyors (DVCCs), two grounded capacitors and two resistors. It can realize all the standard filter functions that are highpass, bandpass, lowpass, notch, and allpass filters by the adjustments of input voltage signals and offer the following features: no requirements for component matching conditions, the use of only grounded capacitors, high input impedance and low active and passive sensitivities.