Trace Width Constraints
To set constraints for trace widths, open OrCAD X Capture Constraint Manager by going to PCB > Constraint Manager.
1. Go to the Physical section on the left of the Constraint Manager window, then go to Physical Constraint Set > All Layers.
Notice we have physical constraints already set. For an exercise, let's say we want 6 mil (0.1524 mm) traces as a standard
routing setting for normal traces, then for high-speed signal traces that need impedance control, let's use 4 mils.
2. Right click the HSD_FPGA element then select Create > Physical CSet…
3. Name the Electrical Constraint Set as PCS1. It gets created (see below).
4. We created an arbitrary Physical Constraint Set named PCS1.
5. Set the Line Width to 6 mils (0.1524 mm).
We can use this constraint set to apply it to any nets that don't need 4 mil widths for impedance control or don't need to be as
narrow as 4 mils. However, note that 6 mil traces give you fewer routing options on a densely populated PCB. It may just be
best to go with 4 mils for every trace if that won't affect cost more than having such narrow traces normally would.
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OrCAD X High-Speed Digital Design Guide
