Decision Feedback Equalizer (DFE) behavioral macro model for packaging system eye diagram transient simulations

摘要

Decision Feedback Equalizer (DFE) [1] is widely used in the high-speed packaging system as a part of receiver for recovering the signal from the distortion by the inter-symbol interference (ISI). Simulating the eye diagram at the receiver output after DFE is helpful to system designers especially in the case there is no longer an open eye diagram at the receiver input. Currently, particular simulation tools or particular algorithm implementations are required to support the modeling and simulation of the DFE function. In this paper, a DFE behavioral macro model is proposed and tested. The proposed DFE behavioral macro model is an HSPICE circuit model and can be used directly in any existing conventional HSPICE compatible transient simulation tools. We use a voltage controlled resistor and a capacitor to model the bit slicer (Symbol Detector) in DFE. The terminated ideal transmission lines with particular delays combined with voltage controlled voltage sources are used for modeling the Feedback Filter (FBF) part of DFE. The summer in DFE is modeled by Directional Junction [2]-[4]. The proposed DFE behavioral macro model can be easily combined directly with existing receiver behavioral macro models targeting other receiver behaviors such as the Mpilog receiver model [5] for accurate receiver input property modeling and the hyperbolic — tangent behavioral model[6] for accurate pre-amplifier/CTLE nonlinear modeling.