Design of low input and high output impedance current-mode biquad filter using CDTAs with independent control of quality factor and pole frequency

Abstract

In this study, a single-input multiple-outputs current-mode analog biquadratic filter, based on current differencing transconducatance amplifier (CDTA) is presented. The proposed filter uses two CDTAs, one resistor and two grounded capacitors, which is well suited for integrated circuit implementation. The circuit simultaneously gives 3 standard transfer functions, namely, lowpass, highpass and bandpass filters with independent control of quality factor and pole frequency by electronic method. By summing of IHP and ILP, the notch filter can be also achieved. Moreover, the circuit possesses low input and high output impedance which would be an ideal choice for current-mode cascading. The PSPICE simulation results are included verifying the workability of the proposed filter. The given results agree well with the theoretical anticipation.