Minimizing Peak Error

The Chebyshev, Chebyshev II, and elliptic filters minimize peak error by accounting for the maximum tolerable error in their frequency response. The maximum tolerable error is the maximum absolute value of the difference between the ideal filter frequency response and the actual filter frequency response. The amount of ripple, in dB, allowed in the frequency response of the filter determines the maximum tolerable error. Depending on the type, the filter minimizes peak error in the passband, stopband, or both.