Versatile current-mode biquad filter using multiple current output OTAs

A current-mode biquadratic filter is introduced using multiple current output Operational Transconductance Amplifiers (OTAs). The circuit configuration has been constructed employing current-mode integrators and a proportional block as basic building units. It is shown that the proposed circuit can realize five different biquadratic transfer functions simultaneously without changing the circuit topology. The effects of OTA non-idealities on the filter characteristics are also discussed. An example is given together with results simulated with PSpice.