cancel
Showing results for 
Search instead for 
Did you mean: 

ADC keeps converting on high External trigger??

nj_boelskov
Associate II
Posted on April 17, 2008 at 11:20

ADC keeps converting on high External trigger??

2 REPLIES 2
nj_boelskov
Associate II
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

jj
Associate II
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.