With TJ Byers
I've always been curious about the difference in IC temperature ratings. What is the difference between commercial and military temperature rating? Is there a way to tell what temp rating an IC is by its part number?
Actually, there are three popular temperature ranges used to grade ICs: commercial, industrial, and military. And yes, you can tell the temperature range by the part's number. In fact, it's the only way you can order them from the manufacturer — by package style and guaranteed temperature operating range. Let's start a chart and let me describe the entries as I expand on their meaning.
The commercial temp range is used indoors, typically in electronic appliances, like radios and TVs. They can operate over a temperature range from freezing (32°F) to steamy hot (158°F). Industrial comes in two strengths, both of which have a much lower operating temperature — all the way down to near Arctic conditions (-40°F). One upper range extends to 185°F, which is adequate for field test equipment and outside surveillance cameras; the other extreme extends to 221°F and is used for automotive applications where temperatures often exceed the boiling point of water. Military is, well military. These devices must withstand conditions which range from the peak of Mt. Everest to the slopes of Mt. Oyama.