Maximum stub exposed length
Set a maximum length for exposed stubs to prevent unintentional antenna effects. This is particularly important for high-fre-
quency signals where wavelengths are shorter. A general rule of thumb is to keep stub lengths below 1/20th of the signal's
wavelength.
Steps:
1. Similar to the stub length rule application, open the CM.
2. Create an electrical CSet in the Electrical Constraint Set > Routing > Wiring worksheet.
3. Once created, scroll horizontally and fill in a max exposed trace length (ideally below 1/20th of signal wavelength) in the
Max Exposed Length field in the row of your desired ECSet.
4. Finally, go to Electrical > Net > Routing > Wiring.
5. Click and apply the appropriate ECSet onto the desired net by selecting the ECSet from the Referenced Electrical CSet
column. The rule is automatically applied to that net.
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OrCAD X Constraint Management Guide
