maximum oscillator trace length


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  1. #1
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    You're welcome.

    Quote Originally Posted by woodygjw
    Steve, you must be on here all the time for me to get an answer that fast!!!
    I was in the past before i answer to too many redundant questions and lazy user that don't want to do some forum search and/or home work.

    Cheers!
    Steve

    It's not a bug, it's a random feature.
    There's no problem, only learning opportunities.

  2. #2
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    Greg,

    it also depends on what type of clock source you are using,
    Resonator, Crystal, Oscillator (w. TTL Output)

    Oscillators are less critical than crystals with external Caps.

    If traces get too long you might have problems for the OSC to start up.

    I personally would never move a crystal 2 inch away from the MCU.

    If it is just the "height" of the crystal causeing the problem:
    a Crystal in HC49U-S package is less in height than a PIC in a DIP package,
    so you might be able to fit one of these.
    SMD crystals are even smaller.
    regards

    Ralph

    _______________________________________________
    There are only 10 types of people:
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  3. #3
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    Hello Ralph,

    Thanks for the response. I am now about 1 inch away so I think all is good. I appreciate the response.

    Greg

  4. #4
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    Don't forget also that long leads on oscillators also produce heaps of radiated signals... your product might fail CE certification if it's a commercial product.

  5. #5
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    Thanks Melanie for your input. I will not be going through any approvals so I think I am OK. Many thanks to all giving their opinion.

    Greg

  6. #6
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    For really small crystals, the Epson mini barrel crystals can't be beat. If you can use a resonator, they already have built in caps in some tiny SMT packages.

    Ron

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