Finding all DC operating points of nonlinear circuits using interval linearization based method

The interval Newton method, which combines the Newton method with the interval arithmetic and branch-and-prune algorithm, has been applied to the problem of finding all direct current operating points of nonlinear circuits. The modified linear programming narrowing technique has also been proposed to improve the computational efficiency of the interval Newton method when applying to a circuit whose nonlinear elements are only diodes and bipolar junction transistors. In this paper, a contraction operator based on interval linearization has been applied to further improve the performances. In addition, the application of the proposed method to circuits containing MOSFET is presented. The numerical experimental results on some test nonlinear circuits indicate that the proposed method can further reduce the number of search boxes and improve the computation time.