Delay extraction based closed-form SPICE compatible passive macromodels for distributed transmission line interconnects

Time-domain macromodeling of highspeed interconnects characterized by distributed transmission lines has generated immense interest during the recent years. It has been demonstrated that, preserving passivity of the macromodel is essential to guarantee a stable global transient simulation. In this paper, a SPICE compatible closed-form passive macromodel for distributed transmission lines is presented. The proposed method enables representation of the distributed stamp in terms of simple delay and resistive elements. The new method while guaranteeing the passivity of the macromodel, provides significant speedup, and enables easy implementation. Necessary formulation and validation examples are given.