semicon temp specs?

M

martin griffith

Guest
been looking at a rf widgit
http://www.nvlsi.no/index.cfm?obj=product&act=display&pro=86#

But it is only spec'd to -20C. What are the chances that it will work
normally down to -40C ie in Canada and other chilly places.

and what happens to an ic working at low temps?


martin
 
Its hard to say how a device would work at lower temperature than
specified and its not wise to do it either. I am sure the company can
test it at -40 deg and send you the data if you contact them.
 
"martin griffith"
been looking at a rf widgit
http://www.nvlsi.no/index.cfm?obj=product&act=display&pro=86#

But it is only spec'd to -20C. What are the chances that it will work
normally down to -40C ie in Canada and other chilly places.
Click to expand...

** It will probably keep working alright - but watch out if it develops
an uncontrollable shaking motion.





........... Phil
 
On Thu, 25 Aug 2005 19:59:59 +1000, in sci.electronics.design "Phil
Allison" <philallison@tpg.com.au> wrote:

"martin griffith"
been looking at a rf widgit
http://www.nvlsi.no/index.cfm?obj=product&act=display&pro=86#

But it is only spec'd to -20C. What are the chances that it will work
normally down to -40C ie in Canada and other chilly places.


** It will probably keep working alright - but watch out if it develops
an uncontrollable shaking motion.





.......... Phil




the ic is so small, I'd put a little heater on it to keep its hands
Click to expand...
warm, so it can still push all them digits


martin
 
"martin griffith"
"Phil Allison"
been looking at a rf widgit
http://www.nvlsi.no/index.cfm?obj=product&act=display&pro=86#

But it is only spec'd to -20C. What are the chances that it will work
normally down to -40C ie in Canada and other chilly places.


** It will probably keep working alright - but watch out if it
develops
an uncontrollable shaking motion.


the ic is so small, I'd put a little heater on it to keep its hands
warm, so it can still push all them digits
Click to expand...

** Seriously - all you need is to attach a 0.5 watt, low value resistor to
the package, feed it some DC and use the heat energy to keep the IC at a
nice temp.

Bound to be cheaper than forking out for "mil spec" devices.



............ Phil
 
Phil Allison <philallison@tpg.com.au> wrote in sci.electronics.design:
"martin griffith"
"Phil Allison"

been looking at a rf widgit
http://www.nvlsi.no/index.cfm?obj=product&act=display&pro=86#

But it is only spec'd to -20C. What are the chances that it will work
normally down to -40C ie in Canada and other chilly places.


** It will probably keep working alright - but watch out if it
develops
an uncontrollable shaking motion.


the ic is so small, I'd put a little heater on it to keep its hands
warm, so it can still push all them digits



** Seriously - all you need is to attach a 0.5 watt, low value resistor to
the package, feed it some DC and use the heat energy to keep the IC at a
nice temp.

Bound to be cheaper than forking out for "mil spec" devices.
Click to expand...
Sure, but if the device has to run at high temperatures too it may not
be quite so simple. Also, low ambient temperature may mean outdoor use,
which may mean battery power, which may mean that using power for heating
is out.

Anno
--
If you want to post a followup via groups.google.com, don't use
the broken "Reply" link at the bottom of the article. Click on
"show options" at the top of the article, then click on the
"Reply" at the bottom of the article headers.
 
"Anno Siegel"
Phil Allison

** Seriously - all you need is to attach a 0.5 watt, low value resistor
to
the package, feed it some DC and use the heat energy to keep the IC at a
nice temp.

Bound to be cheaper than forking out for "mil spec" devices.

Sure, but if the device has to run at high temperatures too it may not
be quite so simple.
Click to expand...

** Sure - when the spec arrives the engineuwrs will play.


Also, low ambient temperature may mean outdoor use,
Click to expand...

** Or inside a fridge, or near the he Arctic.


which may mean battery power,
Click to expand...

** Or a "phantom" powered masthead amp/processor on a TV antenna in Canada.


which may mean that using power for heating is out.
Click to expand...

** Have you considered that the earth may be flat as well ??





........... Phil
 
Phil Allison <philallison@tpg.com.au> wrote in sci.electronics.design:
"Anno Siegel"
Phil Allison

** Seriously - all you need is to attach a 0.5 watt, low value resistor
to
the package, feed it some DC and use the heat energy to keep the IC at a
nice temp.

Bound to be cheaper than forking out for "mil spec" devices.

Sure, but if the device has to run at high temperatures too it may not
be quite so simple.


** Sure - when the spec arrives the engineuwrs will play.


Also, low ambient temperature may mean outdoor use,


** Or inside a fridge, or near the he Arctic.


which may mean battery power,


** Or a "phantom" powered masthead amp/processor on a TV antenna in Canada.


which may mean that using power for heating is out.


** Have you considered that the earth may be flat as well ??
Click to expand...
No, just that the OP hasn't given enough details for an unambiguous
recommendation.

Anno
--
If you want to post a followup via groups.google.com, don't use
the broken "Reply" link at the bottom of the article. Click on
"show options" at the top of the article, then click on the
"Reply" at the bottom of the article headers.
 
On Thu, 25 Aug 2005 22:37:51 +1000, in sci.electronics.design "Phil
Allison" <philallison@tpg.com.au> wrote:

"martin griffith"
"Phil Allison"

been looking at a rf widgit
http://www.nvlsi.no/index.cfm?obj=product&act=display&pro=86#

But it is only spec'd to -20C. What are the chances that it will work
normally down to -40C ie in Canada and other chilly places.


** It will probably keep working alright - but watch out if it
develops
an uncontrollable shaking motion.


the ic is so small, I'd put a little heater on it to keep its hands
warm, so it can still push all them digits



** Seriously - all you need is to attach a 0.5 watt, low value resistor to
the package, feed it some DC and use the heat energy to keep the IC at a
nice temp.

Bound to be cheaper than forking out for "mil spec" devices.

I'd probably use a thermistor + transistor or the LTP in a CA3046
Click to expand...
thing as a temp comparator to turn the heat on and off.This would save
power in hot places
I've never had to do a low or wide temp design, and this was just
comment someone pointed out in another NG discussion

It just interested me


martin
 
"martin griffith"
Phil Allison
** Seriously - all you need is to attach a 0.5 watt, low value resistor
to
the package, feed it some DC and use the heat energy to keep the IC at a
nice temp.

Bound to be cheaper than forking out for "mil spec" devices.

I'd probably use a thermistor + transistor or the LTP in a CA3046
thing as a temp comparator to turn the heat on and off.This would save
power in hot places
Click to expand...

** A PTC thermistor with a sharp temp knee at 25C is the go.

Philips make them as 8mm disks.

One in an old cat ( 2322 661 91005 ) goes from about 25ohms below 0C to
50ohms at 25C to 500 ohms at 50C.

Supply it with about 4 volts rms and voila !




.......... Phil
 
martin griffith wrote:
been looking at a rf widgit
http://www.nvlsi.no/index.cfm?obj=product&act=display&pro=86#

But it is only spec'd to -20C. What are the chances that it will work
normally down to -40C ie in Canada and other chilly places.

and what happens to an ic working at low temps?
Click to expand...
Bipolar stuff has a fermi surface in the impulse
space of the semiconductor lattice. This fermi surface
vanishes toward lower temperatures. When this fermi surface has
vanished to significant degrees I don't know, guess far lower,
-100DegC perhaps. FETs do work downto basically zero.
The next hurdle is the bonding. The bonding wire, usually gold
on silicon doesn't necessarily stick to zero. The different
thermal expansion coefficients of silicon and gold let it
disconnect. Where this happens I don't know either.
Then there may be different thermal expansion coefficient between
carrier and substrate, making the substrate come loose.

As the others said, give it a try.

Rene
--
Ing.Buero R.Tschaggelar - http://www.ibrtses.com
& commercial newsgroups - http://www.talkto.net
 
On Thu, 25 Aug 2005 22:37:51 +1000, "Phil Allison"
<philallison@tpg.com.au> wrote:

"martin griffith"
"Phil Allison"

been looking at a rf widgit
http://www.nvlsi.no/index.cfm?obj=product&act=display&pro=86#

But it is only spec'd to -20C. What are the chances that it will work
normally down to -40C ie in Canada and other chilly places.


** It will probably keep working alright - but watch out if it
develops
an uncontrollable shaking motion.


the ic is so small, I'd put a little heater on it to keep its hands
warm, so it can still push all them digits



** Seriously - all you need is to attach a 0.5 watt, low value resistor to
the package, feed it some DC and use the heat energy to keep the IC at a
nice temp.

Bound to be cheaper than forking out for "mil spec" devices.



........... Phil
Click to expand...

I'm going to be doing a VME card that has to work at -40. We
considered adding one pcb layer that was just a serpentine trace,
driven by a switcher, LM45 for feedback, to warm the whole board.

John
 
On Thu, 25 Aug 2005 17:22:50 +0200, Rene Tschaggelar <none@none.net>
wrote:

martin griffith wrote:
been looking at a rf widgit
http://www.nvlsi.no/index.cfm?obj=product&act=display&pro=86#

But it is only spec'd to -20C. What are the chances that it will work
normally down to -40C ie in Canada and other chilly places.

and what happens to an ic working at low temps?

Bipolar stuff has a fermi surface in the impulse
space of the semiconductor lattice. This fermi surface
vanishes toward lower temperatures. When this fermi surface has
vanished to significant degrees I don't know, guess far lower,
-100DegC perhaps. FETs do work downto basically zero.
The next hurdle is the bonding. The bonding wire, usually gold
on silicon doesn't necessarily stick to zero. The different
thermal expansion coefficients of silicon and gold let it
disconnect. Where this happens I don't know either.
Then there may be different thermal expansion coefficient between
carrier and substrate, making the substrate come loose.

As the others said, give it a try.

Rene
Click to expand...

Diodes and bipolar transistors cave in at around 20K; they call it
"carrier freeze-out" or something. The regular 2.5 mV/K diode slope
has a sharp knee at around 20K. Diodes are used as cryo temperature
sensors down below 2K. As I recall (from some work with Jlab) at 2.5K
a small diode has a few volts drop at 10 uA and looks pretty much
resistive.

Lakeshore makes good cryo diode temp sensors.

John
 
On Thu, 25 Aug 2005 17:22:50 +0200, Rene Tschaggelar <none@none.net>
wrote:

martin griffith wrote:
been looking at a rf widgit
http://www.nvlsi.no/index.cfm?obj=product&act=display&pro=86#

But it is only spec'd to -20C. What are the chances that it will work
normally down to -40C ie in Canada and other chilly places.

and what happens to an ic working at low temps?

Bipolar stuff has a fermi surface in the impulse
space of the semiconductor lattice. This fermi surface
vanishes toward lower temperatures. When this fermi surface has
vanished to significant degrees I don't know, guess far lower,
-100DegC perhaps. FETs do work downto basically zero.
The next hurdle is the bonding. The bonding wire, usually gold
on silicon doesn't necessarily stick to zero. The different
thermal expansion coefficients of silicon and gold let it
disconnect. Where this happens I don't know either.
Then there may be different thermal expansion coefficient between
carrier and substrate, making the substrate come loose.

As the others said, give it a try.

Rene
Click to expand...
This chip itself will generally work below -55°C.

The limitation is packaging. Plastic packages will often crack
adjacent to the lead frame, and are also prone to pulling off
wirebonds since there is only a silastic coating between them and the
plastic.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.
 
On Thu, 25 Aug 2005 09:03:22 -0700, in sci.electronics.design Jim
Thompson <thegreatone@example.com> wrote:

snip
This chip itself will generally work below -55°C.

The limitation is packaging. Plastic packages will often crack
adjacent to the lead frame, and are also prone to pulling off
wirebonds since there is only a silastic coating between them and the
plastic.

...Jim Thompson
Click to expand...
Thanks Jim


martin
 
John Larkin wrote:

Diodes and bipolar transistors cave in at around 20K; they call it
"carrier freeze-out" or something. The regular 2.5 mV/K diode slope
has a sharp knee at around 20K. Diodes are used as cryo temperature
sensors down below 2K. As I recall (from some work with Jlab) at 2.5K
a small diode has a few volts drop at 10 uA and looks pretty much
resistive.

Lakeshore makes good cryo diode temp sensors.

John
Click to expand...
CCDs develop very bad streaks along the transfer direction at low
temperatures (some as high as -50 C, others as low as -100 C), due to
traps becoming unpopulated. So different devices show different
sensitivities to freeze-out. People needing to work at nitrogen
temperature usually stick to majority-carrier devices such as MOSFETs.

Cheers,

Phil Hobbs
 
Phil Allison wrote:
"martin griffith"
"Phil Allison"

been looking at a rf widgit
http://www.nvlsi.no/index.cfm?obj=product&act=display&pro=86#

But it is only spec'd to -20C. What are the chances that it will work
normally down to -40C ie in Canada and other chilly places.


** It will probably keep working alright - but watch out if it
develops
an uncontrollable shaking motion.



the ic is so small, I'd put a little heater on it to keep its hands
warm, so it can still push all them digits




** Seriously - all you need is to attach a 0.5 watt, low value resistor to
the package, feed it some DC and use the heat energy to keep the IC at a
nice temp.

Bound to be cheaper than forking out for "mil spec" devices.



........... Phil
Click to expand...
And never store it below -20°C and never switch it off at such
temperatures...

-- Andy
 
On Thu, 25 Aug 2005 09:03:22 -0700, Jim Thompson
<thegreatone@example.com> wrote:

On Thu, 25 Aug 2005 17:22:50 +0200, Rene Tschaggelar <none@none.net
wrote:

martin griffith wrote:
been looking at a rf widgit
http://www.nvlsi.no/index.cfm?obj=product&act=display&pro=86#

But it is only spec'd to -20C. What are the chances that it will work
normally down to -40C ie in Canada and other chilly places.

and what happens to an ic working at low temps?

Bipolar stuff has a fermi surface in the impulse
space of the semiconductor lattice. This fermi surface
vanishes toward lower temperatures. When this fermi surface has
vanished to significant degrees I don't know, guess far lower,
-100DegC perhaps. FETs do work downto basically zero.
The next hurdle is the bonding. The bonding wire, usually gold
on silicon doesn't necessarily stick to zero. The different
thermal expansion coefficients of silicon and gold let it
disconnect. Where this happens I don't know either.
Then there may be different thermal expansion coefficient between
carrier and substrate, making the substrate come loose.

As the others said, give it a try.

Rene

This chip itself will generally work below -55°C.

The limitation is packaging. Plastic packages will often crack
adjacent to the lead frame, and are also prone to pulling off
wirebonds since there is only a silastic coating between them and the
plastic.

...Jim Thompson
Click to expand...

Anybody got advice/warnings on using, say, a 900 pin BGA in the -40 to
80C range? Is FR4 ok for the board? The bga substrates are usually
FR4, I think, so should match the pcb tce.

I think.

John
 
martin griffith wrote:

been looking at a rf widgit
http://www.nvlsi.no/index.cfm?obj=product&act=display&pro=86#

But it is only spec'd to -20C. What are the chances that it will work
normally down to -40C ie in Canada and other chilly places.

and what happens to an ic working at low temps?


martin
Back in the "good old daze" of MIL-SPEC, many ICs and discretes were
Click to expand...
also characterized and specified to work from -55C to 125C.
Most of those same parts these days have been discontinued - more
eXplicitly, the packages have been discontinued (Cerdip, Metal).
But (for the most part) the processes making those chips has not changed.
I have tested a number of the "plastic" (actually epoxy) parts to
180C, and have found no package problems.
And, except for band-gap voltage references (and parts that use
them), i have found no problems.
On the low temp side, i remember doing "quick" testing of analog
devices by using dry ice.
No problems.
Get some dry ice and test some parts.
If you want a bath to help thermal transfer, use acetone.
 
On Fri, 26 Aug 2005 08:14:57 GMT, Robert Baer
<robertbaer@earthlink.net> wrote:

martin griffith wrote:

been looking at a rf widgit
http://www.nvlsi.no/index.cfm?obj=product&act=display&pro=86#

But it is only spec'd to -20C. What are the chances that it will work
normally down to -40C ie in Canada and other chilly places.

and what happens to an ic working at low temps?


martin
Back in the "good old daze" of MIL-SPEC, many ICs and discretes were
also characterized and specified to work from -55C to 125C.
Most of those same parts these days have been discontinued - more
eXplicitly, the packages have been discontinued (Cerdip, Metal).
But (for the most part) the processes making those chips has not changed.
I have tested a number of the "plastic" (actually epoxy) parts to
180C, and have found no package problems.
And, except for band-gap voltage references (and parts that use
them), i have found no problems.
On the low temp side, i remember doing "quick" testing of analog
devices by using dry ice.
No problems.
Get some dry ice and test some parts.
If you want a bath to help thermal transfer, use acetone.
Click to expand...

I tested a bunch of TO247 power fets hot. At around 300 C, they
spontaneously turned on and quit acting like fets. They were OK when
they cooled off. It took 350 or so to permamently whack them.

John
 
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