Butterworth filters, and to a lesser degree Bessel filters, are probably the most commonly used types of analogue filters. However, in circuits where steep skirts are required it is necessary to us higher-order versions of these filters, which means more components and higher costs. In such cases, a possible alternative is to use a different type of filter, and in particular a Chebyshev filter, since it has considerably steeper skirts for the same order. The only disadvantage of this type of filter is the ripple in the passband and the associated overshoots in the square-wave response (much worse than with Butterworth filters), but it is possible to select component values to control the amount of ripple.
Discussion (0 comments)