New current-feedback amplifier-based universal biquadratic filter

A new universal biquadratic filter configuration using two current feedback amplifiers (CFA´s) is presented. The proposed configuration can realize the second-order lowpass, bandpass, highpass, notch and allpass filters. Both the active and passive sensitivities are no more than unity. The natural frequency ω₀ can be controlled by a grounded capacitor. The quality factor Q can also be independently controlled by a resistor. Moreover, the quality factor will be insensitive to the current tracking errors and output voltage tracking errors of the CFA´s. Experimental results that confirm the theoretical analysis are obtained. The results are useful in analog filtering applications