On low sensitivity/noise digital filter structures

A unified investigation is presented for low-sensitivity, limit-cycle-free filter structures. It is shown that important properties like boundedness and pseudopassivity are closely related to the symmetry of the system matrix description. Implementations by digital circuits are considered. It is demonstrated that symmetric matrix systems can be designed for optimal circuit performance. Sensitivity can be minimized if the deviation of component values is kept symmetric, which can be achieved for a digital filter design by carefully selecting the coefficient truncations