Using Differential Pairs in Allegro PCB Editor
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Differential Pair Calculator
The Differential Pair Calculator is used to perform what-if analysis to determine what
values of the primary gap and width are needed to get specific differential and single-
line impedance.
The calculator is available in the Electrical CSet and Net worksheets in Constraint
Manager, from the Electrical CSet > Routing > Differential Pair and Net > Routing >
Differential Pair worksheets.
To access the differential calculator, in the Primary Gap, Neck Gap, or +/- Tolerance
cells, do the following steps:
4. Right-click and choose Change from the pop-up menu.
5. Select the Calculator button.
You can perform calculations only for edge-coupled differential pairs on a selected
ETCH/CONDUCTOR layer and account for material, thickness, electrical conductivity,
dielectric constant, loss tangent, and shield.
