Abstract
Projection-based model reductions become a necessity for efficient interconnect simulations. In order to choose the order of the reduced system that can really reflect the essential dynamics of the original interconnect, the residual error of the transfer function is considered as a stopping criteria. Analytical expressions of this residual error are derived analytically. This approximate transfer function can also be expressed as the original interconnect model with some additive perturbations. These error information will provide a guideline for the order selection scheme. © 2004 IEEE.