A SPICE-Oriented Method for Finding Multiple DC Solutions in Nonlinear Circuits

Abstract

Finding multiple operating points of nonlinear circuits is a fundamental issue in electronic circuit analysis and design. Methods that guarantee finding all DC solutions are very time-consuming and can be used to analyze only rather small-sized circuits. On the other hand, there exist approaches that can find multiple operating points, but they do not guarantee finding all solutions. The methods are less time-consuming, do not require much computing power, and allow for analyzing more complex circuits. This paper proposes an efficient method for determining multiple and, in most cases, all DC solutions. The approach uses a deflation technique, and the SPICE simulator is applied to the calculations. For this purpose, the original nonlinear circuit during the computational process was modified appropriately after successive solutions were determined. The method was verified on benchmark nonlinear circuits from the literature, made in various technologies and using various models. The results of the DC analysis of several circuits are provided.