1. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
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    I am planning to use separate Vref with ADC.
    My question, is should I bypass the Vref+ or not. The Vref will be taken separate from another circuit with jumper wires less than a feet together with ADC which I want to check.
     
  2. ErnieM

    AAC Fanatic!

    Apr 24, 2011
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    Yes, absolutely add bypass, both at the ref source and at the PIC.

    A bit of series impedance isn't a bad idea either, say 100 ohms to give the cap something to break against.

    And your oscilloscope will be your friend here for design validation.
     
  3. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
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    OK...a 100nf as the Vref+ to bypass it.
    I am not sure why a 100R series with the Vref+
    Can you explain why.
     
  4. ErnieM

    AAC Fanatic!

    Apr 24, 2011
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    It gives the cap something to work against, so the noise stays on the ref side and not on the pic side.
     
  5. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
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    100R at the Vref+ input side and a 100nf at the Vref+ pin of the PIC
     
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