Comments on "The Absolute Stability of High-Order Discrete-Time Systems Utilizing the Saturation Nonlinearity"

It is shown that passivity properties introduced by Mitra for saturation type overflow nonlinearities determine this nonlinear characteristic up to a scaling factor, and that a stability criterion based on these passivity properties can be derived in a different way. It is indicated that this alternative derivation allows a generalization of the criterion to systems with more than one saturation nonlinearity.