A new three-input and one-output current-mode universal filter using unity-gain cells

A new current-mode universal filter using unity-gain current and voltage followers is presented. The filter has three inputs and one output. It offers the following advantageous features: realisation of highpass, bandpass, lowpass, notch, and allpass filter without any changes in the circuit topology, low active and passive sensitivities, no requirement for critical matching, and fewer active and passive elements. Moreover, the current mode circuit is suitable for integrated circuit implementation for using grounded capacitors. PSPICE simulated results that confirm the theoretical analysis are obtained