Current-input Current-output Notch and Bandpass Analog Filter Structures as Alternatives to Active-R Circuits

摘要

This paper reports various current-mode filters that realize notch and bandpass functions without any external passive element. Depending on the circuit, two or more OTAs, and two OPAMPs are employed. These circuits can be considered as alternatives to active-R circuits where the resistance element is also replaced by an active element with controllable transconductance. A comparison between implementation with ICs and discrete components is given. The presented circuits can find application in communication instrumentation.