Using Differential Pairs in Allegro PCB Editor
February 9, 2012 3 Product Version 16.5
Purpose
A differential pair represents a pair of Xnets or Nets routed differentially. The two members
of a differential pair carry the opposite signals. This document covers various aspects of
implementing differential pairs in Allegro PCB Editor.
Audience
This document is intended for Allegro PCB Editor users who want to use differential pairs
in Allegro PCB Editor.
Types of Differential Pairs
Model-defined differential pairs are ones in which the differential pair assignment is done
in the IBIS model.
User-defined differential pairs can be defined in Allegro Design Entry HDL using the
DIFFERENTIAL_PAIR property on nets, or can be created in Constraint Manager. For
High Speed designs, it is recommended to use model-defined differential pairs.
Differential Pair Terminology
