A Very Fast Method for the DC Analysis of Diode-Transistor Circuits

The paper offers a universal method for finding a unique or multiple DC operating points of nonlinear circuits. The developed method is based on the theory known as a linear complementarity problem (LCP) and the homotopy concept. It is a combination of Lemke’s method for solving LCP and some variant of the homotopy method. To express the problem of finding DC operating points in terms of LCP, an appropriate piecewise–linear approximation of diode characteristic is proposed. Although the method does not guarantee finding all the DC operating points, usually it finds them. The method is very fast and remarkably efficient. Numerical examples, including practical BJT and CMOS circuits having a unique or multiple DC operating points are given.