Design of sharp cutoff low-pass maximally flat RC-active filters by cascading third-order blocks

Pairs of coincidentj{ω}-axis zeros are added to the multiple real root maximally flat (MURROMAF) approximation function for designing sharp cutoff low-passRC-active filters. Expressions for transfer function and cutoff slope are derived in terms of the ordern, the multiplicity of the real poleμ, the number of pairs ofj{ω}-axis zerosmand their locations. A design example is also given to illustrate the procedure for finding out the best transfer function.