Design of tunable biquadratic filters employing CCCIIs: state variable block diagram approach
A state variable block diagram method is given for the realization of universal biquadratic transfer functions employing second-generation current-controlled conveyors (CCCIIs). Using minimum number of passive components and properly adjusting the bias currents of CCCIIs, the proposed circuits can realize all the tunable frequency standard filter functions: high-pass, band-pass, low-pass, notch-pass, and all-pass by choosing appropriate input branches without changing the passive elements. These presented circuits are in current-mode and voltage-mode separately. The non-ideality analyses of these configurations are given. Additionally, a high-order low-pass filter derived from the proposed voltage-mode biquadratic filter is introduced. PSPICE simulation results are included to verify the theory.
biquadratic filter cccii state variable block diagram current-mode voltage-mode high-order filter