L298 IC damage without heating

Discussion in 'General Electronics Chat' started by chetan_ec2006, Nov 9, 2010.

  1. chetan_ec2006

    Thread Starter New Member

    Nov 1, 2010
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    Dear Sir,

    i have used L298 drive IC for stepper motor(1A,24VDC) using microcontroller IC.
    When i can connect the motor to driver after 1 to 3 sec driver IC damage without heating. (The upper transistor of winding O3 has been shorted)
    I have use fast recovery diode as UF-4005.
    stepper motor spec. - Portescap - part no 23H218S 003 - 24V, 1A
    I have attach schematic which has been used.
    please give me the right suggestion.
     
  2. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    Can you post your schematic as a PNG format image, or a PDF file if there is a lot of text?
     
  3. chetan_ec2006

    Thread Starter New Member

    Nov 1, 2010
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    0
    dear sir,

    thank for the reply
    please find the png format attachment..
     
  4. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    Is this connected to a uC?

    If the stepper motor has a shorted component, the IC will overheat. How large of a stepper is the motor, and are you using more than one IC? What type of stepper is it? Bipolor or mono?
     
  5. retched

    AAC Fanatic!

    Dec 5, 2009
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    Are the steppers Bipolar or Unipolar?

    If you have wired the motor incorrectly to the driver, you could have shorted the transistor.
     
  6. chetan_ec2006

    Thread Starter New Member

    Nov 1, 2010
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    dear sir,

    thanks for the reply..
    i have used bipolar motor (4 wire), all four wires are connected correctly.
    L298 directly connected to microcontroller.
    whenever i can increase the speed of stepper motor than this problem comes very fast. my query is that am i used UF4005 diode for freewheeling is enough for this ckt.
     
  7. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    What amount of current is the motor pulling, e.g. voltage across Rsense?
     
  8. SgtWookie

    Expert

    Jul 17, 2007
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    Do you have the L298 firmly connected to a rather large heat sink?

    With 1A current flowing through it, the L298 will have a ~3.2v to 4.5v drop across it internally, which means 3.2 to 4.5 Watts power dissipation. Unless you have a rather large heat sink on the IC, you will burn it up within moments.
     
  9. chetan_ec2006

    Thread Starter New Member

    Nov 1, 2010
    6
    0
    dear sir,

    i have used large heaksink also and the amount of current is 1A across sensing resister.
    the IC L298 is not heat.
    Is this problem related with switching diode?
     
  10. SgtWookie

    Expert

    Jul 17, 2007
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    If you are in fact using the UF-4005 diodes that are specified in the schematic, they should be OK.

    Did you buy the L298 driver IC from an authorized distributor? If not, you may have counterfeit parts. Some unscrupulous (dishonest) companies are making very poor-quality parts and labeling them as being made by major manufacturers.

    If you want to be certain that you are getting the genuine item, you need to purchase your parts only from factory authorized distributors.

    Consult the manufacturers' website for their list of authorized distributors.
     
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