Tearing techniques for symbolic simulation of large-scale analog circuits

We present some new tearing techniques to systematically formulate the state equations in symbolic normal-form for linear and/or nonlinear time-invariant large-scale analog circuits with excess elements of both types. Degeneracies of the first and of the second kind are unitarily treated in order to allow a symbolic representation of the circuit with a minimum number of state variables and to identify the eigenvalues equal to zero. An illustrative example is given to prove that our program is a very useful tool for symbolic analysis and design of linear and/or nonlinear time-invariant large-scale analog circuits.