Limit Cycles in Second-Order Digital Filters

Abstract

Limit-cycle oscillations can possibly occur in a digital filter employing finite-precision fixed-point arithmetic under zero (or constant) input conditions. Though a bound was obtained for the magnitude and frequency of oscillation under effective-value linear model, the actual values of the frequency of oscillations obtained by extensive computer simulation are shown to be at variance with the existing theoretical and experimentally determined values. An attempt to explain the discrepancy in the values is made.

Indexing Terms:

• Limit Cycles
• Digital Filters