Duration: 10 minutes | Version Required: 17.4
As a designer, producing a quality design is always of high importance. Part of this process is ensuring you have met all your established constraints through in-design analysis. In-design impedance and coupling checks with OrCAD PCB Designer Professional empower designers to screen a PCB design for signal quality without having to be a signal integrity expert.
This document is intended to provide step by step instructions on how to perform Impedance and Coupling Analysis in your design using OrCAD PCB Designer Professional. For this workshop, download the design files and use the provided design, In-Design Analysis_Start.BRD, to follow along. To view the completed design, select In-Design Analysis_Finish.BRD.
- Open the provided design file, In-Design Analysis_Start.BRD, in OrCAD PCB Designer Professional.
Note: The images and video shown are using OrCAD PCB Designer Professional; however, these steps can also be used to perform analysis in OrCAD Sigrity ERC.
- Select Analyze > Workflow Manager from the menu.
- In Analysis Workflows, choose Select Nets. This will active the XNet Selection Dialog window.
Select all the nets by clicking the >> button in the XNet Selection Tab.
- Click OK.
- Select Start Analysis in the Analysis Workflows Manager. The status of the analysis will be shown in the progress bar.
- When analysis is complete, select the Impedance Vision view. View the Impedance analysis.
- Select Impedance Vision again to exit the view.
- Select Coupling Workflow from the dropdown menu.
- In the Analysis Workflows, choose Select Nets. This will active the XNet Selection dialog window.
Select all the nets by clicking the >> button in the XNet Selection Tab.
- Click OK.
- Select Start Analysis. The status of the analysis will be shown in the progress bar.
- When analysis is complete, choose the Coupling Vision view.
- Move the Coefficient [%] bar until the number reads approximately 11. This will highlight only traces with a coupling coefficient [%] greater than 11.
- View the corresponding traces. To resolve the coupling issue, increase the spacing between the traces.
- Select Setup > Application Mode > Etch Edit from the menu.
- Click a trace to select it and click to place the trace, increasing the spacing between.
- Adjust the spacing for all traces with a higher coupling coefficient.
- Select Start Analysis in the Analysis Workflows tab to view the effect of moving the traces.
- Select Ignore in the Save Existing Results dialog window to continue the analysis without saving.
- Run the analysis.
- View the results. The coupling issues have been resolved and the traces are no longer highlighted.
- To return to normal PCB visibility, select Coupling Vision again and close the Analysis Workflow Manager.
Note: Additional settings are available for the Impedance and Coupling Analysis. For more information, view the blog post: Real-Time Impedance and Coupling Analysis.
Ensuring you have met all your established constraints through impedance and coupling analysis is an essential step in ensuring you produce a quality design. With In-Design Analysis in OrCAD PCB Designer, you don’t have to be a signal integrity expert to screen a PCB Design for signal quality.
If you would like more tutorials, visit our walk-through page to view additional OrCAD and PSpice video tutorials and download design files.
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