Design of voltage-mode multifunction filter using single current operational amplifier

In this study, a new voltage-mode multifunction filter based on single current operational amplifier (COA) is presented. The proposed topology employs single CMOS based COA and it provides lowpass, highpass, bandpass and notch filter functions by modifying only three admittances. The COA used in this study is implemented by CMOS based current conveyors and the validity of the proposed circuit is verified by PSPICE simulation programme. In simulation, the MOSIS 0.35 μm CMOS process parameters are used. It is seen that the simulation results agree very well with the theoretical analysis. Also, the proposed circuit achieves a good THD (Total Harmonic Distortion) performance and the sensitivities of angular frequency to the passive components are shown to be low.