Luis E. Soto wrote:
>
> To you all you PIC experts,
> I am currently working on a project
> that requires about 12 bit resolution A/D converter and that
> can meet the temp requirements of -40 deg C to +125 deg C.
> I Spoke to microchip engineers and they did't have anything
> with that resolution that meets those requirements..
> if you guys have any suggestions please reply soon..
>
> Thanks Lou..

Maybe Linear Tech has 12b Extended or Automotive (synonomous terms)
temperature range parts.  My applications also require high temperature
parts but at 16 to 20 bits - I use the Crystal Semiconductor parts
CS5507-SD (16b) and CS5508-SD (20b).  The 16b part is good to a maximum
of 15b without oversampling so you'd be able to get a good steady 12b
from it.  The 5508 has an rms noise voltage which requires ovesampling
by about 70 to get 20 bits (gaussian noise distribution assumed).  There
are a couple of modes to the serial interface - the ADC can do the data
clocking or your controller can do it.  They're not cheap (no high
temperature part is) and good luck on delivery - plan ahead by 6 to 8
weeks, although Crystal is good at getting you samples.

--Matt