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How to decide the Temperature range of an IC??

rishi2628

I am using a MAX3241E ic in a device that has to run 24x7 out in the open. I am facing a problem deciding the temperature range of the the IC. Since it is out in the open, the ic has to withstand the heat from the sun plus the heating effect due to losses and resistances, etc. I am living in Delhi, India and here the temperature easily reaches 35 degrees. This ic that I have choosen can bear a max temp of 70 degrees. Should I use this ic or should I go for a higher temperature one? Also please tell how should one decide the max temperature of any ic?

 

Datasheet of the IC: - http://www.mouser.com/ds/2/256/MAX3222E-MAX3246E-99333.pdf

  • 0

    Now I have done it!  I have hipped JWT to thermo-electrics!  I just know he is going to invent a solar-powered back that will keep the kielbasa warm while keeping the earthworms, string-cheese and Leininkugel's cool. He will offer it in red-and-white and green-and-yellow trim. He will clean up once again. 

     

    I will be left once again, following the Bears, pondering if G-d really does love the poor.

  • 0

    This can be a complex question - lots of factors to consider as indicated in this article:

    Silicon ICs can stand about 150 junction temperature, but their (plastic) package may lose pin seal at lower temperatures due to the difference in coefficient of thermal expansion between plastic and metal, allowing moisture in at the pins. This can dramatically shorten the life of the IC.

    If you encapsulate (pot) your circuit to exclude moisture, a 70 C chip may survive higher temperatures, but you may need to be more careful about self heating calculations to avoid junction temperatures above 150 C.

    Temperature can affect transistor switching times, so some chips may not work correctly at high temperature even though there is no thermal damage.

    If you plan to put your circuit in direct sunlight, try to shade it with a highly reflective cover, as the sun can supply about 1 kW per square meter.

  • 0 in reply to D_Hersey

    Hi Don,

     

    I have never found you annoying just very informative and entertaining. I have entered the translation of TEC in my list. G-d must love the poor, there are so many of them.

     

    John

  • 0

    On the topic of TECs, I would like to try to use them for crystal growing.  I would pour a nearly boiling saturated solution of, say, copper sulphate, into a squarish glass container.  I would have washed the vessel carefully with distilled water.  The container would be on a board which rests on a partially-inflated dirt-bike inner-tube, to isolate our experiment from mechanical vibration.  I'd use TECs and maybe a heater to slew the solution to near-freezing, hoping to extract a large crystal.