FTFN based dual inputs current-mode allpass inverse filters

Abstract

In this study, four new configurations implementing first-order current-mode allpass inverse filter signals are presented. The proposed generic circuit with two inputs and a single output employs a single FTFN, three resistors and a capacitor with both the inputs supporting the first-order allpass inverse responses separately. The topologies offer high output impedance,

which enable easy cascading in current-mode. The realizability condition is simple and temperature invariant, being in the ratio of two grounded resistors. The additional advantage of the circuit is that the phase can be controlled by adjusting the values of passive components without disturbing the realizability condition. The tracking error performance for the filters has also been studied. The simulation results are also included.