David Quint, Ph.D., Master Engineer, Hewlett-Packard

Modeling of the power delivery system for IC 's can be initimidating and confusing. This paper presents three approaches to this task, using the example of a DIMM board power design. The first approach develops a comprehensive 3-D SPICE simulation which provides detailed knowledge of the DIMM system. This knowledge is then used to generate a greatly simplified SPICE model that mimics the terminal characteristics of the DIMM. This condensed model can then be used multiple times in the next heirarchy, which is a large memory board. Finally, a method of producing the card model is proposed which uses only minimum design data but produces a reasonable model valid from DC to the first (zero order) resonance of the power subsystem.