Low Sensitivity Third Order Lowpass Butterworth Filter Using CFA
R. Nandi, Mousiki Kar and Soumik Das
A third-order lowpass (LP) Butterworth filter design scheme using two CFA devices is presented. The analysis is carried out utilising the parasitic and transadmittance poles of the AD−844 type CFA elements. The circuit is practically active−insensitive with respect to the port mismatch errors (∈) of the devices. The filter characteristic had been satisfactorily verified with both PSPICE macromodel simulation and hardware circuit implementation for a frequency range 6 MHz ≤ fo ≤ 30 MHz.
Keywords: Butterworth filter, lowpass filter, third-order filter, CFA