DP83867IR: Schematic review request

GukHyun Lee

Intellectual 260 points

Part Number: DP83867IR
Other Parts Discussed in Thread: AM3352

Hi expert.

I am drawing a schematic with dp83867

Could you check if the Schematic has something?

I'm gonna use a am3352 processor and connect with RGMII interface.

I attached schematic.

And I wonder what I should connect power line from PMIC to dp83867.

I attached PMIC schematic, then please let me know.

Really thanks.

12 ETHERNET.pdf 05 PMIC.pdf

over 3 years ago

0 Hillman Lin over 3 years ago

TI__Mastermind 25955 points

Hi Lee,

I went over your DP83867 Schematic and put some comments on it. Here is something you might need to pay attention to:

Change Rbias resistor value to 11k ohms.
Double check on the termination for the RGMII receiver since 867 PHY have in-build termination
Double check on the RJ45 schematic to the magnetic connections on 867 datasheet.
If possible, isolate the cable ground to the PHY ground.

867schematic.pdf

Regards,

Hillman Lin

0 GukHyun Lee over 3 years ago in reply to Hillman Lin

Intellectual 260 points

thanks!

Double check on the termination for the RGMII receiver since 867 PHY have in-build termination

-> I copied the resister from some schematic. I checked "Troubleshooing guide" then will eliminate those resisters . However, I guess that traces between MAC and PHY should have specific impedance determined by trace width. Am I right?

0 Hillman Lin over 3 years ago in reply to GukHyun Lee

TI__Mastermind 25955 points

Hi Lee,

There will be 50 ohms in-build termination with in 867 PHY for RGMII pins
Yes, you are correct. Please refer to the design layout checklist to determine the traces width:

https://www.ti.com/lit/an/snla387/snla387.pdf?ts=1646952732208&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FDP83867IR

Regards,

Hillman Lin

Interface

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DP83867IR: Schematic review request