How to identify unstable DC operating points

The stability of operating points that satisfy the circuit´s DC operations but are nonetheless unobservable operating points is examined in a rigorous way. Two classes of DC operating points, unstable and potentially stable, are defined, and simple criteria, based only on the circuit´s DC equations, that can classify a given operating point´s stability are given. It is also shown that it suffices to model stray capacitance and inductance in only certain specific locations, for any given physical circuit, to correctly assess the stability of its operating point in the presence of a profusion of parasitic reactances