Versatile current-mode universal biquadratic filter using plus-type dual-output ICCIIs

摘要

In this paper, a versatile three-input and three-output universal current-mode biquadratic filter is proposed. The circuit employs three plus-type dual-output inverting second-generation current conveyors (DO-ICCIIs) as active elements together with three grounded resistors and two grounded capacitors. The proposed configuration exhibits high-output impedance which is important for easy cascading in the current-mode operations. It can be used as either a single-input three-output or three-input two-output circuit. In the operation of single-input and three-output circuit, the lowpass, bandpass and bandreject can be realized simultaneously while the highpass filtering response can be easily obtained by connecting appropriate output current directly without using additional stages. In the operation of three-input and two-output circuit, all five generic filtering functions can be easily realized by selecting different three input current signals. The filter permits orthogonal controllability of the quality factor and resonance angular frequency and no component matching conditions or invertingtype input current signals are imposed. All the passive and active sensitivities are low. Post-layout simulations are based on using TSMC 0.18μm 1P6M CMOS process technology and supply voltages ±0.9V to verify the theoretical analysis.