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Original question:

TLIN1021-Q1: Unused WAKE/ INH/ SPLIT pin connection

TLIN1021-Q1: LIN signal integrity of TLIN1021-Q1

yansong.wei
Prodigy 90 points
Part Number: TLIN1021-Q1
Other Parts Discussed in Thread: TLIN1021A-Q1

Hi,

For LIN communication, i have one question,  refer to the figure below.

For the input interface, the LIN signal reference is GND2.

Based on EMI considerations, the 12V loop needs a common mode inductance filter.

Then the TLIN1021-Q1's power supply use 12V and GND, not 12V_IN and GND2.

Based on the discontinuity of the ground signal, the signal integrity of the LIN signal is problematic.

How to solve this?

Thanks.

  • 0
    TI__Guru 73542 points

    Yansong,

    We'll take a look at this and get back to you next week with a reply. Thank you for your patience.

    Regards,

    Eric Hackett

  • 0 in reply to Eric Hackett
    Prodigy 90 points

    Hi,Eric

    Could you help to solve that?

  • 0 in reply to yansong.wei
    TI__Guru 73542 points

    Yansong,

    We are still looking into this and will get back to you.

    Regards,

    Eric Hackett

  • 0
    TI__Mastermind 26786 points

    Yansong,

    Please evaluate the TLIN1021A-Q1 in place of the TLIN1021-Q1.

    The LIN signal that is interpreted by the LIN transceiver is based upon its input supply voltage. If the potential on the left side of your figure shifts relative to the right side of the figure, that means that the signal on LIN will change relative to "12V" and "GND" references. Depending on the difference, this could cause communication loss or could even damage the transceiver. Given the need for this common mode filter, I am assuming your system is expecting significant voltage transients.

    LIN transceivers are intended to share a common supply and ground potential across the bus. My recommendation would be to implement TLIN1021A-Q1 on the left side of the bus, using 12V_IN and GND2. After this, it might be necessary to do some signal conditioning on TXD/RXD to step them down to the appropriate MCU voltage, but then your communication is much more likely to be maintained.

    If the potential difference between "12V_IN" and "12V" is not expected to be significant, then this might be unnecessary.

    Best,

    Danny