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 Termination resistors 

Last post Thu, Oct 4 2007 10:05 PM by archive. 5 replies.
Started by archive 04 Oct 2007 10:05 PM. Topic has 5 replies and 824 views
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  • Thu, Oct 4 2007 10:05 PM

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    Termination resistors Reply

    Hi,

    Can anyone explain what is the need of termination resistors and also how they can be placed such that its need is met.


    Thanks in advance


    Originally posted in cdnusers.org by kingshar
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  • Fri, Oct 5 2007 4:09 AM

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    RE: Termination resistors Reply

    The most common termination resistor is a source termination. It is used to match the output impedance of a driver to the transmission line impedance to reduce overshoots and undershoots. It should be placed as close as possible to the driver. Practially speaking, a distance of 750 mils is usually acceptable unless you have a very fast driver such as a high frequency clock fan out buffer.


    Originally posted in cdnusers.org by Kalevi2
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  • Fri, Oct 5 2007 5:02 AM

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    RE: Termination resistors Reply

    Thank you very much ,Kai Keskinen

    Regards,
    Sarath Kumar


    Originally posted in cdnusers.org by kingshar
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  • Fri, Oct 5 2007 11:04 PM

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    RE: Termination resistors Reply

    PCB traces should be terminated when the trace length exceeds the following condition:

    Length > tr / (2 x t pd )

    Where tr = Signal rise time, t pd = Signal propagation delay.
    Most used termination types:

    Series [Source] Termination :
    should only be used with one load on the line, but only requires one resistor [R], placed near the source.
    Parallel Termination :
    Used with any number of loads.Requires one resistor,placed near the receiver.
    Thevenin Termination [or Split Termination]:Placed near the receiver.

    Regards,
    Satya Shankar.G
    at&s Ecad.


    Originally posted in cdnusers.org by satya1234
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  • Mon, Nov 12 2007 1:54 AM

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    RE: Termination resistors Reply

    Thank you satya


    Originally posted in cdnusers.org by kingshar
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  • Thu, Nov 15 2007 11:59 PM

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    RE: Termination resistors Reply

    Hi satya,
    You discussed about series and parallel termination and that was really nice. can u make me clear about other terminations ex Differential , AC, Thevenin.
    And what are the conditions for each of them to be used?

    It would be so nice of you!!!

    Thanks and regards
    Niraj


    Originally posted in cdnusers.org by nforniraj
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Started by archive at 04 Oct 2007 10:05 PM. Topic has 5 replies.