Lpc1549 bug in acmp?

The datasheet about analog comparator acmp that response to 250nsec pulse
width. However we found issue that it missing pulse unless more. Than
100usec.

Has anyone experience this issue and workatound.

We report the bug in nxp forum but no response 


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Posted through http://www.EmbeddedRelated.com

On Tue, 18 Oct 2016 08:06:25 -0500, riscy00 wrote:

> The datasheet about analog comparator acmp that response to 250nsec
> pulse width. However we found issue that it missing pulse unless more.
> Than 100usec.
> 
> Has anyone experience this issue and workatound.
> 
> We report the bug in nxp forum but no response
> 
> 
> ---------------------------------------
> Posted through http://www.EmbeddedRelated.com

No answers, but some possibilities to chase:

* Are you driving it hard?  Comparators are amplifiers inside, and
  are slower when you give them smaller differential input.  The
  rated speeds are for 50mV overdrive; if you're hitting it with
  something smaller than that, expect slower response (if any --
  it should have some hysteresis, although I didn't look it up).

* Do you have the thing set to maximum speed?  From a light reading
  of the data sheet, you can program the comparator propagation time

* Is it the comparator?  Could whatever follow-on logic that you're
  using be the culprit?



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