It is difficult to envision what actual circuit and plane topology you created in HyperLynx PI to represent the schematic that you sketched. Can you provide the design file or a picture of the layout? The tool might be assuming something that is different from your intended configuration. There are many options to set in the decoupling wizard. Can you provide some details about the options you selected in the wizard?
If you have hyperlynx 9.3 or higher you should be able to do this with the advanced decoupling wizard.
But you will need to change a setting to enable model assignment on the resistor:
Setup → Options → General → [Power Integrity] and enable 'Allow AC supply models for non-capacitor components'.
You can then add the resistance + inductance value or a model.
See https://support.mentor.com/knowledge-base/MG595587 for more information
I received only a circuit picture from my customer.
so I did a test with a simple data.
As you requested, I have attached the data.
and please refer to pictures below.
GNDAGND2_PCB.zip 15.1 KB
I checked the option and then set the resistor value in the advanced decoupling analysis.
But the decaps weren't reflected in the impedance between power net and AGND net.
I have attached the details above.
so you can refer to them.
Sending the design file was the key to the solution. This way I can see that the resistor is not actually connected from GND to AGND. The pin over the GND area does not have a via to connect it from top layer to bottom layer.
I exported the power nets to LineSim so that I could add the connection from top to bottom. This requires a few tricks, but you can do it easier by editing the layout and bringing it into BoardSim again. Anyway, with the resistor connected between GND and AGND, I got these impedance results.
Z11 is 3V3 to GND, and Z22 (upper curve) is 3V3 to AGND.
You might have already figured this out, but the Advanced Decoupling Wizard is required in this case so that you can define the pin pairs for probing since the reference nets do not have metal at the location of the power pins.
Thank you for reviewing the sample.
I connected the resistor to GND net and finally got a right result.
I really appreciate your help.
Meeojeong, I'm glad yours questions were answered. Please mark the 'Correct Answer' button so that others will know your question was resolved.