Dwayne Reid wrote:
>
> Sorry for the Off Topic-ness of this message, but I need advice.  I have to
> mount a bypass capacitor near a temperature sensor that will be subjected to
> temperatures ranging from -45 C to + 120 C.  I would like to use tantalum (1
> uf / 35 Vdc operating at 5 Vdc) but my data sheets don't talk about
> reliability at high temperatures.
>
> I am hoping some of the down-hole instrument people can tell what they use.

Trade secrets?  Well, I guess that capacitor facts aren't all _that_
secret.  Typically, I don't like tantalum - they self-destruct into a
"shorted" mode, as opposed to ceramic that "open up".  We stick to
ceramic up to 0.1uF - after that they get a little large for our
down-hole stuff.  That said, we have had no problems with tantalum at
150degC.  It looks like you're watching the voltage derating - 35V is
definately playing safe.  I think that you should be OK.

--Matt
>
> Dwayne Reid   <dwayner@planet.eon.net>
> Trinity Electronics Systems Ltd    Edmonton, Alberta, CANADA

BTW, what are you doing working on a holiday? :-)

--
Matthew Bonner B.Eng. - Sunada Technology Corp. - Calgary, Alberta
mailto:mbonner@sunada.com