DP83848K: FLP out of spec with Ethernet compliance done with TPM

Seb O

Part Number: DP83848K

Dear,

I am doing a Ethernet Compliance test on Fast Link Pulse (FLP) after we get issue with negotiations with some switched.

When the Ethernet compliance is done on DP83848K with LOAD1, LOAD2 and 50ohms only as specified in Ethernet all is good, but, when the Twisted Pair Model (TPM) is added before the load as specified in Ethernet standard for the compliance test, the FLP drops too much and the test fail.

What could be the root cause of such issue?

What parameter could helps to "boot" FLP pulse level and edges?

Sébastien

over 7 years ago

0 Marty Shank over 7 years ago

TI__Intellectual 2100 points

Correction: test was done with 100Ohms load, not 50Ohms as stated above.

0 Ross Pimentel over 6 years ago in reply to Marty Shank

TI__Mastermind 23675 points

Can you please share the results so we can see by how much the failures are?
Also, please send the schematic.
What cable length are you using for the tests?
What is the test setup? i.e. LeCroy, R&S, Keysight, Tek?

0 Seb O over 6 years ago in reply to Ross Pimentel

Intellectual 515 points

Hi,

I had a side discuss with TI technical support. I think I've found the issue. One inductor on the TPM circuit is damaged. I've order a new one am waiting for it. I will mark this issue as Resolved as soon as I've made the test with it.

I am using TEK compliance tool suite.

Sébastien

0 Ross Pimentel over 6 years ago in reply to Seb O

TI__Mastermind 23675 points

Hi Sebastien,

Thank you for letting me know.

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DP83848K: FLP out of spec with Ethernet compliance done with TPM