Effect of Loop Delay on Phase Margin of First-Order and Second-Order Control Loops

Abstract

This paper analyzes the phase margin of first-order and second-order control loops in the presence of a loop delay and establishes rules of thumb on the maximum permissible delay for a given phase margin. Both discrete-time and continuous-time loops are considered. Results are applicable, for example, to adaptive filters and to first-order and second-order phase-locked loops. © 2005, The Institute of Electrical and Electronics Engineers, Inc. All rights reserved.