Noise estimation system for board‐level electrical circuit–calculation of capacitance coefficient of multiconductor system by calcap

Abstract

AbstractNetwork analysis with equivalent lumped constant circuits is effective for evaluating the noise generated on a circuit board considered as a total electronic circuit system. This paper considers the partial capacitance calculation program (CALCAP) that is used for expressing the pattern wiring in terms of equivalent lumped constant parameters within a loaded design system (NESSY) insensitive to the noise. In the CALCAP, three‐dimensional orientations of multiconductors on a substrate are considered and the formulations have been done with the image method and the integral equations. As a tool in a system, the CALCAP is designed for ease of parameter input and routine work, and for high‐speed execution. To this end, a nonuniform sampling algorithm is used. The capacitance of an isolated equipotential parallel plate has been computed and the dividing methods have been compared. The present method was found to be superior to others. The capacitance of parallel plates and strip lines have been computed using the present method. For the strip lines, appropriate measures have been obtained for: (1) the segmentation method; and (2) the length of the cell. Further, the capacitance has been measured and the cross‐talk experiment has been performed for a simple model of strip lines. The results of the capacitance calculation and those of the circuit simulation have been compared and found to be in good agreement.