Suppression of limit cycles in second-order companion form digital filters with saturation arithmetic

A condition for second-order companion form digital filters with time variant nondeterministic saturation overflow arithmetic to be free of limit cycles was previously given by Ooba. The condition corresponds to a region which is a subset of the stability triangle. In the present paper, time invariant deterministic saturation nonlinearities are considered. It is shown that, with such nonlinearities, the system is free of limit cycles in whole of the stability triangle.