Purpose: Impedance control is used to specify and maintain consistent characteristic impedance for high-speed signal
traces throughout the PCB.
Steps to Execute Constraint for Impedance Control:
1. Open the Constraint Manager.
2. Navigate to the Electrical Constraint Set > Impedance.
3. Define target impedance values for different trace types (e.g., single-ended).
4. You can then go to the Electrical > Net > Routing > Impedance worksheet and apply the constraint to any net, net class,
or net group.
5. Then, you can determine whether the nets are adhering to the rules inside the constraint set by right-clicking a net
name and then clicking Analyze.
6. The analysis will show red, yellow or green for whether your net complies with the Single line impedance constraint.
7. It lets you know the target impedance, the tolerance, the actual impedance of the trace, and the margin (how much you
are in terms of impedance).
5 www.cadence.com
OrCAD X Constraint Management Guide
