Electronically tunable current-mode universal biquadratic filter using CCCDBAs

This paper introduces a current-mode universal biquadratic filter using current controlled current differencing buffered amplifiers (CCCDBAs). The filter circuit is constructed with two CCCDBAs, two current controlled current differencing amplifiers (CCCDAs) and two grounded capacitors. The circuit can realize low-pass, band-pass, high-pass, band-stop and all-pass transfer functions by choosing appropriate current output terminals without any component matching conditions. Additionally, the circuit parameters omega₀ and Q can be set orthogonally through adjusting the bias currents. The biquadratic filter enjoys very low sensitivities with respect to the circuit components. An example is given together with simulated results by PSPICE.