Anti-Alias Filter Type Selection Guide

A variety of 8-pole filter types are available for the AAF line from Alligator Technologies. Please use the information below to select the best filter for your application or contact Alligator Technologies for assistance.

FILTER TYPE	STRENGTH/WEAKNESS	APPLICATION
Cauer	Good passband flatness and low noise with sharpest cutoff; non-uniform group delay	For frequency-domainapplications requiring a sharp cutoff; also useful inthe time domain
Bessel	Uniform group delay;lowest wideband noise; drooping amplitude response in the frequency domain; gentler cutoff frequency	For time-domain applications requiring minimum distortion of rapid slope changes
Butterworth	Best passband flatness and very low noise; non-uniform group delay (but more uniform than Cauer filters) and gentler cutoff slope	For frequency-domain applications requiring minimum noise or maximum passband flatness
High-Speed Cauer	Similar to Cauer with lower noise as well as higher cutoff frequency and higher stopband rejection; non-uniform group delay (more uniform than Cauer)	Similar applications to Cauer, but with a need for a cutoff higher than 50 kHz or a higher stopband rejection
High-Speed Linear Phase	Highest maximum cutoff frequency; sharper cutoff than Bessel; reduced input/outputvoltage limits	For highest-speed applications, especially in the time domain