A computer program for the analysis of integrated circuits (CAIC) is described. The program formulates and solves nonlinear equations for dc node voltages and transistor operating points, generates small-signal circuit models and solves for input, output and transfer impedances and the phase and frequency response of a specified transfer function. Modified Newton-Raphson method (combination of BIAS-3 and CANCER algorithm) is used for the fast convergence and requires fewer iteration steps to reach dc solution. The program also does large-signal transient analysis with automatic time-step adjustment. The choice of the time step is based on comparison of the results computed with different step lengths and the integration formula used is trapezoidal rule. The diffusion capacitance as a function of current through, and transition capacitance as function of voltage of, the diode is taken into account in this analysis. These subanalysis capabilities are intercoupled appropriately for convenience and efficiency. Two examples of analysis, an operational amplifier and emitter-coupled multivibrator are presented that illustrate the computational efficiency of the program.
展开▼
