[EFM] Extended Temperature Optics
(forgive the wide distribution, but I'm sort of trawling for info...)
I've done a preliminary search on the origin of the fabled "-40 to +85 C"
This is what I've found.
Various semiconductor companies talk about these ranges. Most often, they
as ambient temperature (Ta). In cases where serious power is being
dissipated, a de-rating
curve or equation is supplied, and in some cases, certain air-flow rates are
there is a lot of inconsistency in the industry. For example, Allegro says
Operating Temperature Range.
C =Commercial (0 °C to +70 °C)
S =Standard (-20 °C to +85 °C)
E =Extended automotive/industrial (-40 °C to +85 °C)
G =Extended industrial (-40 °C to +105 °C)
J =Extended industrial (-40 °C to +115 °C)
K =Industrial/military (-40 °C to +125 °C)
L =Automotive/military (-40 °C to +150 °C)
X =Special (i.e.,wafer probe at +25 °C only)
While National Semiconductor says:
In general, the temperature ranges are defined as follows:
Military: -55 to +125'C
Industrial -40 to +85'C (some variation, check datasheet)
Commercial 0 to +70'C
Automotive -40 to +125'C (some variation, check datasheet)
Note that in this case, even the specification indicates that it is not
I found two standards that talk about temperature:
There is the Mil Spec: MIL-STD-883E 1012.1
This talks about either Case or Mounting surface temperature, and NOT
(In fact, they give a diagram showing how you should build a liquid cooled
heat sink to
clamp the case temperature to the tested value.) This document specifies a
of temperatures, including -55 to +85 and -55 to +125. It seems the
concerned about attacking cold places (Siberia?) as well as hot.
There is also JEDEC A105-B "Power and Temperature Cycling"
This talks about testing such that "the entire mass of each device under
test to reach
the specified temperature extremes". This would seem to be a 'case'
And, it requires the power to be turned on and off during the test (kind of
like a soak test).
However, this test is considered destructive and is for device
Specifies temperature ranges of -40 to +85 and -40 to +125 C.
That is what I've found so far. I can't say that this is very definitive,
and I looks to
me like the electronics industry has avoided this issue. I invite anybody
any other information to please contribute it to the group.
I'll save the rest of my comments for the optics exploder.