DP83867IS: Issue of DP83867

Duc Ngo HHD

Part Number: DP83867IS

Dear Ti,

My customer is having issue as below.

They are using DP83867ISRGZT. When customer connect to network devices (laptop or router/switch,..) need few minutes to connect at baud rate at 1Gbps. Normally following standard about 2-5s for connecting.

They have tried as https://e2e.ti.com/support/interface-group/interface/f/interface-forum/1015081/dp83867is-how-to-shorten-the-link-up-time?tisearch=e2e-sitesearch&keymatch=DP83867IS%2520time#, but having issue.

Pls help to check and advise.

Thanks!

over 2 years ago

0 Kallikuppa Sreenivasa over 2 years ago

TI__Guru** 123888 points

Hello Duc Ngo HHD,

Thank you for the query.

What is the link partner customer is using.

Does this delay happen with a specific link partner ?

Regards,

Sreenivasa

0 Duc Ngo HHD over 2 years ago in reply to Kallikuppa Sreenivasa

Prodigy 20 points

Hi Sreenivasa,

Customer is following https://e2e.ti.com/support/interface-group/interface/f/interface-forum/1015081/dp83867is-how-to-shorten-the-link-up-time?tisearch=e2e-sitesearch&keymatch=DP83867IS%2520time#.

Does this delay happen with a specific link partner ? --> yes, when customer connect to switch/router.

Thanks,

Duc

0 Kallikuppa Sreenivasa over 2 years ago in reply to Duc Ngo HHD

TI__Guru** 123888 points

Hello Duc Ngo HHD

Thank you for the reply.

Customer has this issue with specific switch. When the is testing with other devices, the link up time is fine.

The link you shared is for 100M and customer seem to be testing at 1G. Is this understanding correct.

Can you ask customer to disable auto MDIX and test.

Would customer be ok to share the schematics.

Regards,

Sreenivasa

0 Duc Ngo HHD over 2 years ago in reply to Kallikuppa Sreenivasa

Prodigy 20 points

Hi Sreenivasa,

- Customer is testing with switch of TPlink, and sw kzs9897 of Microchip. Customer tested with laptop, somtimes having same issue.

- Can you ask customer to disable auto MDIX and test? --> Customer tried, but same issue

- Would customer be ok to share the schematics? --> yes

Best regards,

Duc

0 Kallikuppa Sreenivasa over 2 years ago in reply to Duc Ngo HHD

TI__Guru** 123888 points

Hello Duc Ngo HHD

Thank you for the reply and inputs.

The auto nego and the auto mdix contribute majorly for the link delay.

You mentioned customer did not see any difference with the auto MDIX enable or disabled. is this understanding correct ?

Regards,

Sreenivasa

0 Kallikuppa Sreenivasa over 2 years ago in reply to Kallikuppa Sreenivasa

TI__Guru** 123888 points

Hello Duc Ngo HHD

Could you please ask customer to share he RJ45 interface schematics.

Regards,

Sreenivasa

0 Duc Ngo HHD over 2 years ago in reply to Kallikuppa Sreenivasa

Prodigy 20 points

Hi Sreenivasa,

You mentioned customer did not see any difference with the auto MDIX enable or disabled. is this understanding correct ? --> yes.

Could you please ask customer to share he RJ45 interface schematics.

--> Customer connects directly to transformer.

Best regards,

Duc

0 Kallikuppa Sreenivasa over 2 years ago in reply to Duc Ngo HHD

TI__Guru** 123888 points

Hello Duc Ngo HHD

Thank you for the query.

Regarding the magnetics, i am interested in understanding how the termination is done. Schematics would help.

Could you please ask customer of fix the speed to 1G for testing.

Regards,

Sreenivasa

0 Duc Ngo HHD over 2 years ago in reply to Kallikuppa Sreenivasa

Prodigy 20 points

Hi Sreenivasa,

Schematic customer shared as previous message.

Customer tested at 1G, but same issue.

Best regards,

0 Kallikuppa Sreenivasa over 2 years ago in reply to Duc Ngo HHD

TI__Guru** 123888 points

Hello Duc Ngo HHD

Thank you for the reply.

If i understand correctly, with auto nego disabled, with 1G speed set manually the link time is few minutes (2or more).

We expect the linkup time to be 100s of ms without auto nego and MDIX enabled.

In the above schematics shared, i do not see the magnetics part. Can you please ask customer to provide the same.

Regard,

Sreenivasa

0 Duc Ngo HHD over 2 years ago in reply to Kallikuppa Sreenivasa

Prodigy 20 points

Hi Sreenivasa,

Yes, you're correct but customer tested without auto nego and MDIX enabled - still delay few minutes.

Transformer customer is using https://www.digikey.com/en/products/detail/w%C3%BCrth-elektronik/749020111/2682558.

Best regards,

Duc Ngo

0 Duc Ngo HHD over 2 years ago in reply to Duc Ngo HHD

Prodigy 20 points

Hi Hi Sreenivasa,

FYI.

With competitor part (AR8031^Qualcom), customer tested with all switch --> no delay

But, Ti part, customer has issue with some switches, some laptop,....

Best regards,

0 Kallikuppa Sreenivasa over 2 years ago in reply to Duc Ngo HHD

TI__Guru** 123888 points

Hello Duc Ngo HHD

Thank you for the reply and info on the external magnetics.

Could you please check if the center taps of the magnetics on the PHY side are shorted. We do not recommend shoring the center taps.

Regards,

Sreenivasa

0 Kallikuppa Sreenivasa over 2 years ago in reply to Duc Ngo HHD

TI__Guru** 123888 points

Hello Duc Ngo HHD

Thank you for the inputs.

Any thoughts on the cable length customer is using ?

I see that the customer is using 3 supply option. Can you please ask customer to check if the supply levels are Ok.

I also see that the load caps used are 39 pF. This could be on the higher side. Can you please check if customer has tested with 27pF caps?

Regards,

Sreenivasa

0 Kallikuppa Sreenivasa over 2 years ago in reply to Kallikuppa Sreenivasa

TI__Guru** 123888 points

Hello Duc Ngo HHD

I also see that the load caps used are 39 pF for the crystal oscillator. This could be on the higher side. Can you please check if customer has tested with lower value caps. Example is 27pF caps?

Regards,

Sreenivasa