Determining potentially unstable operating points using time-varying root-locus

The application of time-varying root-locus (TVRL) algorithm for transient analysis of electronic circuits with potentially unstable operating points is presented. The TVRL algorithm calculates the dynamic movement of evolving characteristic equation roots by computing them at a sequence of time instants during the circuit transient. This TVRL indicates the existence of potentially unstable operating points. An LC-filter with Q-enhancement is used as example to demonstrate the dynamics of the circuit characteristic equation roots during power supply transient.