Challenges and opportunities for determining presence of multiple equilibrium points with circuit simulators

Challenges of using standard circuit simulators to determine the presence or absence of undesired operating points are discussed. Examples are given of circuits and simulation strategies that show the presence of undesired operating points when they exist but other examples are given that show the same strategies can fail to show the presence of undesired operating points under modestly different simulation conditions. Since many of the most widely used analog and mixed-signal circuits that are known to be vulnerable to the multiple equilibrium point problem have no standard electrical inputs, it is shown that a temperature parametric analysis sweeping method may be useful in some applications for identifying the presence of undesired operating points.