Single and Multi-Piece Behavioral Models of IC Output Buffers

This paper discusses the switching properties of the behavioral models of integrated circuit output buffers. Present behavioral models are based on a two-piece structure defined by a linear combination of two submodels for the two logic states. These models are very accurate in the two logic states, but their state switching is sensitive to the driven loads. The analysis carried out in this paper shows that this load sensitivity stems from the linear combination defining the two-piece model. A new single-piece behavioral model is proposed, that solves this problem and has efficiency and complexity levels comparable to those of two-piece models.