SK-AM62B-P1: Impedance Calculation for High-Speed Traces on SK-AM62B-P1

Hello Arijit

Thank you for the query.

The data sheet includes the PCB connectivity requirements

Example shown below

The below FAQ includes links for key collaterals including the data sheet and target impedance for the core supply.

 https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1183910/faq-am625-custom-board-hardware-design-collaterals-to-get-started 

The below fAQ inlcudes likns to general high speed design guides including DDR design guide.

 https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1551120/faq-am625-am623-am620-q1-am62l-am64x-am243x-alv-am62ax-am62d-q1-am62px-board-layout-links-to-documents-for-general-high-speed-layout-guidelines 

Regards,

Sreenivasa

Hello Arijit

Arijit Mohanty said:

My confusion: calculations for asymmetric stripline, microstrip using IPC formulas differ from values implied in the SK-AM62B-P1 design.

Could you please summarize the difference you are seeing.

Regards,

Sreenivasa

Hello Sir

The difference I’m seeing is that my calculated impedance values using standard formulas don’t match the impedance I assume was targeted on the SK-AM62B-P1 board. I’d like to know the exact impedance targets that TI used for each high-speed interface so I can align my custom design. 

e.g: For USB Type-c diff. microstrip trace on Layer 1,  By considering it's properties like trace width,spacing,Cu thickness. dielectric height, Er, coupling factor-  I got the Zdiff around 68Ω, where the target impedance for USB2.0 should be 90-100Ω.

like that for  ddr4 single end microstrip on layer 10 , I got the calculated impedance around 41Ω, where target impedance is 50Ω
So  I’d like to know the exact impedance targets for each high-speed interface with respect to board properties.

Hello Arijit

Thank you.

The FAQ that i shared above can help answer some of the queries.

We recommend customer to follow the SK as the SK has been simulated as well as tested.

Let me check if there are any additional inputs that i can get from the simulation team.

Regards,

Sreenivasa

Yes Sir Please let me know your team’s response.
Additionally, if I submit my design files, would your team be able to review them, run the required simulations, and provide simulation report?  I do not have the necessary simulation tools.

Hello Arijit

Thank you.

We do not support PCB layout review or provide simulation support.

You may have to work with a third party.

In case you are working with a TI sales or support, you can reach to them 

Regards,

Sreenivasa

Ok sir

Do let me know about it,

Kallikuppa Sreenivasa said:

Let me check if there are any additional inputs that i can get from the simulation team.

Thank you

Hello Arijit

Thank you.

Please review the above FAQ and the application notes that are lined in the E2Es as i check internally.

Regards,

Sreenivasa