New second-order low-pass, high-pass and band-pass filters employing minimum number of active and passive elements

Two voltage-mode second-order filter configurations are presented. The presented configurations employ minimum number of active and passive elements, namely one differential difference current conveyor (DDCC) as active element and two capacitors and two resistors as passive elements. The proposed filters can realize the low-pass, high-pass and band-pass responses. The new configurations offer very high input impedance, which enables easy cascading and enjoy low sensitivities. The natural frequency ω_o and the quality factor Q of the filters are orthogonally adjustable. Simulation results, which confirm the validity of the theoretical analysis, are given to the two configurations.