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  1. #1
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    uln2803 hot

    I'm making a stepper driver with ULN2803. It's working, but the IC heats up very quickly. I'm not using microstepping. I'm using two outputs paralleld together, totaling one ULN IC per driver (8 outputs / 2 = 4 outputs, as needed for uniploar driving).

    Is it safe to operate the ULN in high temps?Or should I get some cooling? Is there cooling for DIP packages?

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  2. #2
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    ic uln2803 php

    You should limit the current or decrease the supply voltage



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    uln2803 heat

    There are heatsinks for DIP.
    See Fischer ( http://www.fischerelektronik.de/index.php?id=29&L=1 ) or Aavid
    Take for example a look at Farnell: art# 4620896

    But you have to calculate what is safe. Calculate the thermal resistance of the heatsink to get the ic below breakdown temperature.



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  4. #4
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    Re: Driving steppers with ULN2803

    Hi

    No it is not safe to operate at high temperatures.....
    Also u soulh use heat sink...probably u`r motor has high amp(ic has
    500 mA)....and that is why
    the ic get hot.I attach pdf for ic maybe it helps.



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