This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TLK106: The LED_LINK pin is on but the Link Status bit is 0

Part Number: TLK106

Hello,

I connected the device (via RG45 transformer XFMATM9) to Laptop.

The LED_LINK pin is on but the Link Status bit of the Status Register is 0.

The content of Status Register is 0x7849.

I tried also with loop back cable. Same occurrence.

Can you please advise me?

Thanks.

Yacob Hassidim.

19 Replies

  • Hi yacob,

    Are you using a custom board or the TLK106 evm?

    Can you share the schematic of your phy if it's a custom board?

    Are you reading register 0x1 multiple times?

    Best regards,

    Rob Rodrigues

    EFL (Ethernet & FPD Link) Applications Engineer

  • In reply to Rob Rodrigues:

    Hello Rob,

    Thank you for your reaspond.

    This is a custom board.

    Attached please find the schematic diagram of TLK106.

    I read the register 0x1 repeatly and receive the same result.

    Sincerely,

    Yacob.

  • In reply to Yacob Hassidim9:

    Yacob,

    The Rbias resistor for the tlk106 needs to be 4.87k 1% ohm. This value is critical to operation of the phy. Please replace that resistor with the proper value.

    Best regards,

    Rob Rodrigues

    EFL (Ethernet & FPD Link) Applications Engineer

  • In reply to Rob Rodrigues:

    Hello Rob,

    Thank you for your fast repsone.

    I understand to replace the R324 to 4.87K.

    What about C184 (100 pF)?

    Sincerely,

    Yacob Hassidim.
  • In reply to Yacob Hassidim9:

    Hi Yacob,

    I would recommend removing C184. I do not see a large impact, but it is unnecessary. Please let me know how your HW change turns out.

    Best Regards,

    Rob Rodrigues

    EFL (Ethernet & FPD Link) Applications Engineer

  • In reply to Rob Rodrigues:

    Hello Rob,

    Thank you for your suggestions.

    I will inform you about the result of HW changes.

    By the way the datasheet has not reference diagram for Rbias like Figures 3-1 and 3-2.

    Can you please ask them to add figure also Rbias?

    Sincerely,

    Yacob Hassidim.
  • In reply to Yacob Hassidim9:

    Hello Rob,

    I replaced the R324 by 4.86 KOhm.

    I didn't remove the C184 yet.

    Unfortunately the link status bit is 0 (while the LED link is on).

    The value of status register is 0x7849.

    Can you please advise me?

    Sincerely,

  • In reply to Yacob Hassidim9:

    Hello Rob,

    I replaced the C184 also.

    No change.

    Can you please advise me?

    Sincerely,

    Yacob Hassidim.
  • In reply to Yacob Hassidim9:

    Hello Rob.

    I removed the C184 also.

    No change.

    Can you please advise me?

    Sincerely,

    Yacob Hassidim.

  • In reply to Yacob Hassidim9:

    Hi Yacob,

    OK, that was the first thing I saw was an issue.  I'd like you to check the following items.

    1. Look at timing of input reference clock PHY_2_CLK.  If PHY_2_CLK is not stable when the TLK106 power comes up, you may need to apply a RESET pulse to the TLK106 to initialize properly.

    2. Measure RBIAS voltage during normal operation (should be approximately 1.2V)

    3. Remove L37 and replace with 0 ohm resistor

    4. Ensure PFBOUT is ~1.55V +/- 5%

    5. Put the TLK106 in digital loopback mode and check for a link up in register 0x1

    Best Regards,

    Rob Rodrigues

    EFL (Ethernet & FPD Link) Applications Engineer

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.