Three input single output current mode biquad filter using single VDTA

This paper presents a new filter structure based on single voltage differencing trans-conductance amplifier (VDTA) which is capable of realizing all five current-mode biquad filtering functions by the use of three current input signals. In addition of using single VDTA, the presented current-mode structure also employs three grounded passive elements in the form of two capacitors and one resistor and hence, the circuit is suitable for IC fabrication. Apart from these, the proposed filter also enjoys few more desirable features such as low value of sensitivities and low value of power consumption. The PSPICE based simulation results of the proposed circuit in 0.18μm CMOS process technology are included in the paper.