L6203 driver heating up

Discussion in 'The Projects Forum' started by armandoevangelista17, Oct 29, 2012.

  1. armandoevangelista17

    Thread Starter New Member

    Oct 29, 2012
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    Hi! I've been making a DC motor driver using the L6203. Apparently I've read that it's very durable but the problem is the driver keeps on heating up and possibly going on thermal shutdown. I've followed the circuit on the L6203 datasheet with the exception of the L6205 current controller. Can anyone give a suggestion why the L6203 keeps on heating up and going on a possible thermal shutdown? thanks!
     
  2. t06afre

    AAC Fanatic!

    May 11, 2009
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    Some questions here ;) Do you have any schematics. How much current do the motor draw. What kind of IC package do you use. One more thing. Do the your circuit work as it should before heating up.
     
  3. armandoevangelista17

    Thread Starter New Member

    Oct 29, 2012
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    the motor draws 3.75A at max. The l6203 is a transistor package. I've attached the eagle file of the schematic and a picture of it.
     
  4. t06afre

    AAC Fanatic!

    May 11, 2009
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    I think you have look at your thermal management. Each transistor will have an on-resistance equal to 0.3. And in a H-bridge the current have to pass through two transistors. So by using this you can calculate the power dissipation at any given duty cycle. I assume you have not used any heat sink. Your chip has a maximum Thermal Resistance Junction-ambient equal to 35 °C/W. By using this as help. You will be able to do all the needed calculations http://www.jaycar.com.au/images_uploaded/heatsink.pdf
    But as you will see it is no surprise that your chip overheat and shut down. You have to use a heat sink ;)
     
  5. armandoevangelista17

    Thread Starter New Member

    Oct 29, 2012
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    yeah i have used a heatsink + thermal paste with each driver. but the problem still persists
     
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