[Diy_efi] Project/temperature ranges

[Torbjörn Forsman]

It seems like there are no simple standardized temperature ranges for 
electronic components today, one must read the fine print of each 
datasheet instead of just specifying for example "industrial".
There are many cases where "industrial" components are specified -25 ... 
+85 ?C, for example. Some "commercial" components are specified 0 ... 
+135 ?C , the reason for this is to allow more self heating and come 
away with a simpler thermal design (smaller cooler etc).

There are many cases where manufacturers do their own tests on 
components or complete systems to determine if they can safely be used 
beyond the component manufacturer's spec. This is very common on 
industrial PC motherboards today, as many motherboard components 
(ethernet controllers, multi I/O chips, graphics controllers) are not 
available in other than commercial temperature range. I have recently 
seen an ethernet controller specified for 0 ... +65 ?C in a military 
computer which is specified for -46 ... +49 ?C storage and -40 ... +75 
?C operation. I know that both the manufacturer and the customer for 
this PC has done extensive climate tests and found it to pass the tests.
In many cases, one can accept minor deviations from the datasheet's data 
at -40 ?C, say for example that an amplifier for a car radio has 
somewhat higher crossover distortion than specified. But the part must 
not totally cease working at low temperatures, and must not be damaged 
by running at extreme temperatures!

Many manufacturers uses to specify -25 ... +85 ?C or -40 ... +85 ?C for 
general automotive electronics, but the maximum temperature is +110 ?C 
for under-the hood components.

Best regards

Torbj?rn Forsman


Alex Ruiz wrote:
> "Why would GM find it necessary to use the 'automotive' range in their
> ECM/PCMs? "
> 
> Maybe because their ECM/PCM needs to work in Alaska and somewhere else
> in India where the ambient temp at night may be towards 44?C.
> 
> 
> 2007/2/27, gassr <gassr at charter.net>:
> 
>> I agree.
>> Why would GM find it necessary to use the 'automotive' range in their
>> ECM/PCMs? Asking about using 'automotive' range in automotive 
>> applications
>> may sound silly, but it appears to be a question of using components with
>> suspect (at least min.) parameters or going the
>> distance on both ends, as even the 85?C range could be considered
>> questionable for underhood temps.
>>
>> Gary
>>
>> ----- Original Message -----
>> From: "Bill Lewis" <bill at wrljet.com>
>> To: <diy_efi at diy-efi.org>
>> Sent: Tuesday, February 27, 2007 8:50 AM
>> Subject: Re: [Diy_efi] Project/temperature ranges
>> >
>> > It's really the low side that you might worry about in an
>> > automotive application, since 0?C isn't very cold at all.
>> >
>> > Bill
>> >
>> > Joe Vitek wrote:
>> >>
>> >> Commercial range is 0? to +70?C. Industrial is -40? to +85?C. 
>> Automotive
>> >> range is really tough at -40?C to +125?C.
>> >>
>> >>> How does the temp range for 'commercial' differ from 'automotive'?
>> >>> I'm led to believe 'automotive' is designed to function within a 
>> wider
>> >>> range of temp variation, with both a lower -?C and higher +?C. If so,
>> >>> why deviate from automotive application norms?
>>
>>
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