Issue link: https://resources.pcb.cadence.com/i/1534759
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, actual impedance of the trace and margin (how much off you are in terms of impedance). Note: The behavior of the trace will be such that when you're routing it, the trace thickness will change to maintain the impedance, or at least a DRC error will appear if your trace falls outside the target impedance range. Reason: Controlled impedance is crucial for maintaining signal integrity in high-speed circuits. It helps minimize signal reflections, reduce crosstalk, and ensure proper signal transmission. Specify target impedance values (e.g., 50Ω for single-ended traces, 100Ω for differential pairs) to minimize reflections and ensure compatibility with specific communication protocols. This involves controlling trace width, spacing, and dielectric properties. Impact on the Board: f Improves signal quality and reduces distortion in high-speed signals (by reducing reflections) f Enhances overall system performance and reliability f May require specific PCB materials and manufacturing processes to achieve desired impedance values f Can influence trace routing and layer stack-up decisions By implementing proper impedance control constraints, designers can ensure that high-speed signals maintain their integrity throughout the PCB, leading to more reliable and higher-performing electronic products. Crosstalk Mitigation: Maximum parallel trace length Diagram illustrating crosstalk between two traces running parallel to each other. Purpose: Limit the length that signal traces run parallel to each other to reduce coupling and crosstalk. This is especially crucial for high-speed differential pairs. The acceptable length depends on factors like trace spacing, layer stack-up, and signal frequency. In this example, you will learn how the Constraint Manager prevents excessive coupling among traces. 51 www.cadence.com OrCAD X High-Speed Digital Design Guide