A method for finding bounds on all the DC solutions of transistor circuits

A new effective method is developed for finding bounds on the location of all the DC solutions of the circuits containing Ebers-Moll-modeled transistors and diodes. The circuit is represented by algebraic equations consisting of linear and nonlinear (exponential-type) parts. The method leads to the process of successive contraction of a region including all the solutions. The crucial point of the method is weakening the nonlinearities using a real parameter which can be generally optimized. In this way it follows a very simple computation process rapidly convergent to the bounds on the solutions. An effective implementation of the method is described and numerical examples are given