An Enhanced Stability Criterion for Strict Passive Analysis of Digital Filters

The present study establishes a very-strict passivity stability condition for digital filters subjected to external disturbance employing saturation nonlinearities. It is shown that proposed criterion is more relaxed than a few existing works in the literature. When external disturbance goes to zero, a result for asymptotic stability of the digital filter employing saturation overflow arithmetic is made available. The established conditions are in linear matrix inequality framework, hence easily tractable. Numerical examples are put in order to demonstrate the efficacy of the formulated stability conditions.