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IBIS Models Support in Eldo
Package
Package
IBIS has many ways for package modeling, differing in their complexity and accuracy. The
simplest, least accurate, way is to assume all the package pins are identical and uncoupled.
The common package parasitics, R_pkg, L_pkg and C_pkg shown in Figure 17-12, are defined
under the [Package] keyword in the IBIS file. Each pin is assumed to have parasitic resistance
R_pkg, inductance L_pkg, and capacitance C_pkg. Unique parasitics R_pin, L_pin and C_pin
can also be defined separately for each pin under the [Pin] keyword.
Figure 17-12. Common Package Parasitics
More advanced package modeling can be achieved using the [Package Model] keyword, where
you can refer to a package model inside the .ibis file or in a .pkg file. You can model the
package as coupled pins and give the resistance, inductance and capacitance matrices (RLC
matrices) elements of the package pins network. These matrices assume the Maxwellian format.
Another way of modeling is to divide the package into stub sections and define the electrical
parameters for each section. The stub represents the physical connection between the package
pin and the die pad. Each section is described in terms of its L/R/C per unit length and the Fork
and Endfork subparameters allow any path to branch. For example, this can describe the
parasitics of the wire bond between the die pad and the package pin. This stub can be treated as
lumped or distributed elements depending on whether the section length is 0 or not.
Related Topics
IBIS Package
Supported Keywords and Sub-Parameters
744
Eldo® User's Manual, 15.3