Dual Input Single Output Digitally Controlled Biquadratic Filter

In this paper a Digitally controlled Dual Input Single Output biquadratic filter has been presented. The filter utilizes two Differential Voltage Current Conveyors as the active elements, the passive elements utilized are three grounded resistors and two grounded capacitors. The circuit successfully realizes digitally controlled Low pass and Band pass filter responses. The current summing network employed in the internal circuitry of DVCC, incorporates the digital control in it. Tuning of cut-off frequency is done using a 3- bit digital control word. The circuit has been simulated using 0.25 micron TSMC parameters on PSPICE, to validate the theoretically analyzed results.