Analysis of BJT circuits having multiple DC solutions using deflation technique

The paper is focused on the analysis of diode-transistor circuits having multiple DC solutions. The transistors are characterized by the Ebers-Moll model consisting of two pairs of diode - controlled source combinations and contact resistors. An idea of deformation of the equation describing the circuit, in such a way that it avoids the solutions earlier determined and retains the remaining solutions, called a deflation, is applied. This idea is combined with the discrete circuit equivalent of the Newton-Raphson modified nodal analysis. An efficient deflation technique is developed, enabling us to find multiple DC solutions of rather large-sized circuits. To illustrate the proposed approach a numerical example is given.