Novel electronically tunable current-mode filter without external passive elements

摘要

This paper presents a current-mode filter with a general class of circuit transfer functions using active devices only. This circuit employs Operational Amplifiers (OAs) and multiple current output Operational Transconductance Amplifiers (OTAs) as the basic building units. It is shown that the circuit can realize various filter characteristics by choosing the current output branches. It is also shown that the circuit provides electronically tuning capability of the filter characteristics. An example is shown with the simulated results by PSpice.