Using Differential Pairs in Allegro PCB Editor
February 9, 2012 8 Product Version 16.5
Max Uncoupled Length
The maximum length for which the two nets of differential pair can run uncoupled is
constrained by the constraint, MAX_UNCOUPLED_LENGTH. This constraint is
available in the Differential pair worksheet. If the two nets of the differential pair do not
follow the gap constraints for certain length which is more than the
MAX_UNCOUPLED_LENGTH constraint, the uncoupled length DRC is shown as D-U,
and the uncoupled segments are highlighted as displayed in the following image:
Tandem Routing
You might need to route the two nets of differential pair on adjacent layers. This does not
happen automatically in Allegro PCB Editor or Router. However, it is possible to tandem
route differential pairs manually.
