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DS90LV804: LVDS Repeater Rated for -55C

Jeff Richelsoph
Prodigy 90 points
Part Number: DS90LV804
Other Parts Discussed in Thread: SN55LVCP22

Tool/software:

Hello.  The DS90LV804 is the function I need but it is only rated to -40C.   Is there a similar part rated to operate at -55C?   Actual use will be at -43C.   Thank you.

  • 0
    TI__Expert 3170 points

    Hi Jeff,

    Can you provide more information about where -43C is coming form? Is that ambient temp, air flow temp, board temp, case temp?

    Regards,

    Jack

  • 0 in reply to Jack Campbell
    Prodigy 90 points

    Hello Jack.  Here is the story.  This design is a test board designed to test a DUT.  The designers of the DUT changed the design low temperature requirement from -37C to -40C, and convinced those in power that we must design the TE to work at -43C.  +/-3C is a typical chamber tolerance.  In order to do that, I've used -55C rated parts.  However, the only part I found suitable as a clock repeater is the SN65LVDS179MDGKREP, connecting the receiver output (pin 2) to the buffer input (pin 3).   Hopefully the inline picture I posted will show.

    The problem with this I'm concerned about this circuit passing a 260MHz input clock.  I've asked a signal integrity SME if they can simulate this.

    An alternative, is to use a DS90LV804TSQ/NOPB but this part is only rated to -40.  No -55C part shows in a parametric search.  To do this I have two possibilities.   1) screen the parts to -43C operation or 2) obtain documentation that the parts are already tested with some margin.

    Thank you.

    Jeff

  • 0 in reply to Jeff Richelsoph
    TI__Expert 3170 points

    Hi Jeff,

    Thanks for the additional info. I share your concern regarding the 260MHz clock signal. That transceiver is only rated up to 200MHz.

    You are also correct that we do not have any buffers rated beyond -40C. If -55C is a hard requirement I would recommend SN55LVCP22. It is an LVDS crosspoint switch capable of being configured as a buffer. It can meet both your temperature and speed requirements.

    If you have more info regarding this project and if there would be interest in a -55C rated LVDS buffer, should one be available in the future, please let me know and we can connect offline.

    Regards,

    Jack