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nj_boelskov
Associate III
April 17, 2008
Question

ADC keeps converting on high External trigger??

  • April 17, 2008
  • 2 replies
  • 677 views
Posted on April 17, 2008 at 11:20

ADC keeps converting on high External trigger??

    This topic has been closed for replies.

    2 replies

    jj_it
    Associate II
    May 17, 2011
    Posted on May 17, 2011 at 12:30

    ADC will start the conversion on a rising edge:

    Can't tell if you are questioning the ref manual -

    it appears that you HAVE generated a rising edge -

    but of uncertain/unspecified duration. Seems easy

    to prolong this signal and simply observe...

    Months ago we capacitor coupled to this trigger pin -

    eliminating a too-wide input. (our notes don't show

    IF multiple readings resulted - although one fellow

    thinks he recalls we had ''accuracy/stability'' issue)

    You will get the best answer with a small, simple Eval

    Bd - should you not have your Bd. done. We try to have

    a small group read a chapter - generate questions - and

    then we confirm and document on multiple parts multiple boards.

    Finally - we used a Cpld to emit ''high-going'' one-shot

    into the STM trigger. Readings are dead stable.

    nj_boelskov
    Associate III
    May 17, 2011
    Posted on May 17, 2011 at 12:30

    Hi

    If you use an external trigger for ADC-trigger, the ref-manual says that the ADC will start the conversion on a rising edge, and it is true. If the external trigger signal then stay high, will the ADC then keep converting untill the triggersignal is set to low, even though the ADC is not set to continus mode?

    -Boelskov