A formulation method for including ideal operational amplifiers in modified nodal analysis

摘要

Two approaches are presented that allow circuits with ideal operational amplifiers to be characterized using modified nodal analysis (MNA). The first method, referred to as the long-hand approach, is a trivial extension of the KCL equation generation method using a nullor model for the opamp. The method is rather tedious and requires manipulation of the rows and columns of the MNA matrix to account for the existence of the opamps. The second method develops a dual element stamp for all the elements allowed by MNA to account for connectivity to ideal opamps in the circuit. This approach is very efficient and directly produces the MNA matrix for the circuit from the element stamps, eliminating the need for any manipulation of the matrix, and preserving the advantages of MNA element stamp formulation techniques.