(ALMOST) HALF OF ANY CIRCUITS OPERATING POINTS ARE UNSTABLE

This paper presents new results concerning the stability of operating points of dc circuits. We define two classes of unstable operating poi nts and develop criteria for identifying the class to which a given op erating point belongs. We also show, by employing results from degree theory, that if a circuit possesses n structurally stable operating po ints (n has been shown previously to be odd), then 1/2(n - 1) of these operating points must be unstable and hence physically unobservable. A special case of this result proves that any bistable circuit must po ssess at least three operating points.