Current-tunable current-mode universal filter using minimum elements

In this paper, a new electronically tunable current-mode universal filter with three inputs and single output employing only two translinear current conveyors and two grounded capacitors is presented. The proposed configuration provides lowpass, bandpass, highpass, bandstop and allpass current responses by choosing appropriate input signals without any component matching conditions, all at a high impedance output which enables easy cascading in the current-mode operation. The filter also offers independent electronic control of the natural frequency (omega_o) and the quality factor (Q) through adjusting of the bias current and the current gain of the CCCII. The parameter sensitivities are all very low and the structure is very suitable for IC implementation. The characteristics of the proposed circuit are simulated using PSPICE to confirm the theory.