Simultaneous switch noise modeling for high performance ASIC

Texas Instruments ASIC Division (TI) has developed a highly accurate and flexible statistical characterization technique using equations to predict output switching noise. A 21-term polynomial equation is described which accurately predicts the number of ground and V/sub cc/ pins required for a given design as nonlinear functions of the number of outputs switching simultaneously, the number of active outputs which are not switching, the ground or V/sub cc/ noise levels allowed, the package pin inductances and transmission line characteristics of the loads. The accuracy and flexibility of this technique is contrasted with traditional, less sophisticated methods.<>