2P products temp range question for Parallax
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Posts: 46,084
I'm planning an application which needs to operate at outside
temperature. What are the plans for extended temperature operating
range for the 2P products?
Chuck H.
temperature. What are the plans for extended temperature operating
range for the 2P products?
Chuck H.
Comments
The BS2p operates at a temperature range of 32F to 158F. We don't have
any current plans for an extended temperature version (which would
depend on the availability of the resonator and SX chip at the
industrial rating).
The BS2SX-IC operates at a temperature range of -40F to 185F since it
uses an industrial-rated SX28.
The BS2I-IC also operates at this temperature range.
http://www.parallax.com/detail.asp?product_id=BS2I-IC
Let me know if you have any other questions.
Sincerely,
Erik Wood
ewood@p...
Parallax, Inc.
599 Menlo Dr., Suite #100
Rocklin, CA 95765
(916) 624-8333
www.parallax.com
Original Message
From: chuck_33708 [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=dT7_JweSMQV3j2eQmP2-4lPdKVoHhrwid37VghEll3HAUH3GSS8SaXDlsrIKBDmWCKVlnZlPiUbG87E]ch12@n...[/url
Sent: Monday, April 14, 2003 2:22 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] 2P products temp range question for Parallax
I'm planning an application which needs to operate at outside
temperature. What are the plans for extended temperature operating
range for the 2P products?
Chuck H.
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> The BS2p operates at a temperature range of 32F to 158F. We don't have
> any current plans for an extended temperature version (which would
> depend on the availability of the resonator and SX chip at the
> industrial rating).
Thanks for the reply Erik.
That's too bad. Boy that's going to make it tough to do any outdoor applications
isn't it? Like automobile, trucks, RV's, environmental data logging, winter
hobbies, GPS, etc. I happen to live in Florida, so I guess I won't have to
worry about it unless I move or if decide to sell something in the future.
A related question Erik. I'm NOT questioning your answer at all, just looking
for some free advice. After I wrote the original message I took a look at the
Ubicom web site. The datasheets showed "Ambient temperature under bias" as -40C
to 85C. I assumed this was the allowed operating temperature. Now I conclude
not. In general, not just SX, how does one find out the allowed operating
temperature for devices? It makes a difference, both high and low, for
applications I have in mind.
Regards,
Chuck H.
The SX48DB-I/TQ is in fact rated -40 to +85 and that is the one that
is used on the BS2p and BS2pe now in production. The Catalyst eeprom
is also industrial rated, 24WC256KI. I don't know about the
resonator (20mhz on the '2p and 8mhz on the '2pe.) I've used the
Stamps at temperatures in the -20 degree C range with no problems,
and sometimes they get pretty hot too, in boxes in the sun.
The biggest problem the Ubicom 'sx chips have with temperature
extremes is oscillator startup (after a period of sleep, for
example). I think the engineering staff at Parallax did put a lot of
work into choosing the capacitors and the feedback to make that
circuit reliable. But it is up to them to make the guarantees for
the operating temperature range.
Recently I have been making my own data loggers out of OEM chips, and
all of the parts including the SX48 chips are rated for the
industrial temperature range, and I'm using a Murata resonator rated
-20 to +80 (couldn't get the one rated -40 to +125). Even so, it is
necessary to validate the operation at temperature extremes. It
might be a matter of 1 in 200 not working, so if it really matters,
test it before deployment.
The other problem with temperature extremes, and especially with
rapid temperature changes, is microcracks that form in the chip next
to the lead frame, and when moisture gets in the cracks and
freezes... well, it eventually leads to failure. The incidence of
that has a lot to do with the stresses left in the package after
soldering or in the circuit board at the time of mounting, and with
the control of the moisture and thermal environment that the chips
are subjected to.
-- best regards
Tracy Allen
electronically monitored ecosystems
http://www.emesystems.com
mailto:tracy@e...
>--- In basicstamps@yahoogroups.com, "Erik Wood" <ewood@p...> wrote:
>> The BS2p operates at a temperature range of 32F to 158F. We don't have
>> any current plans for an extended temperature version (which would
>> depend on the availability of the resonator and SX chip at the
>> industrial rating).
>
>Thanks for the reply Erik.
>That's too bad. Boy that's going to make it tough to do any outdoor
>applications isn't it? Like automobile, trucks, RV's, environmental
>data logging, winter hobbies, GPS, etc. I happen to live in
>Florida, so I guess I won't have to worry about it unless I move or
>if decide to sell something in the future.
>
>A related question Erik. I'm NOT questioning your answer at all,
>just looking for some free advice. After I wrote the original
>message I took a look at the Ubicom web site. The datasheets showed
>"Ambient temperature under bias" as -40C to 85C. I assumed this was
>the allowed operating temperature. Now I conclude not. In general,
>not just SX, how does one find out the allowed operating temperature
>for devices? It makes a difference, both high and low, for
>applications I have in mind.
>
>Regards,
>Chuck H.
> The SX48DB-I/TQ is in fact rated -40 to +85 and that is the one
..........
> I've used the Stamps at temperatures in the -20 degree C range with no
problems,
> and sometimes they get pretty hot too, in boxes in the sun.
.....
>
Thanks for the info Tracy. Nice to know it won't be a big problem and just have
to be careful. I can understand how Parallax needs to be conservative in their
ratings.
Chuck H.