Lpc2000

--- In lpc2000@yahoogroups.com, Charles Manning <manningc2@a...>
wrote:
> On Friday 11 February 2005 04:07, fl429 wrote:
> > Hi, Folks,
> >
> > Has anyone tried these chips in a very high temp environment,
around
> > 150C, typical downhole in the gas and oil industry ? How do they
> > fare ?
> >
> > Thanks a lot,
> 
> If parts are only rated to 70C or so, then running them at 150 would
seem to 
> be asking for trouble. I'd think that if you designed a 70C part
into an 150C 
> environment you'd find a bunch of lawyers gnawing on your bones
pretty soon. 
> I'd design in a higher-temp part or use peltier cooling etc to get
the temp 
> in the right range for the part.
> 
> There are some things you can do to promote reliable operation under
higher 
> temperatures. The most important is probably to run at slower clock
speeds.

I have never done downhole designs myself, but my understanding is
that they don't expect units to be long lived.  They can consider them
to be expendable if they work ok until they poop out.  As long as the
MTBF does not go to minutes, which I don't expect, running at 150 C
should be no biggie.  But like you said, the part will need to be run
at a slower speed because of the slower silicon speed at higher
temps.  

Peltier might be an interesting way to cool such a part, but they are
also semiconductor (not sure of the material) and may also poop out at
high temps.