IGBT Pulsed measurement

Discussion in 'General Electronics Chat' started by kanoun, Jan 29, 2015.

  1. kanoun

    Thread Starter Member

    Jan 29, 2015
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    I’m trying to make a pulsed IV caracterics (Ic-Vce) of an IGBT ref IKA10N60T. The aim is to have the output characteristics with no self heating. The pulse duration is about 100µs and the period is 50 ms. I’m using this set up. I have two different problems:

    The Vce signal is very noisy

    I have a 2A delta when compared to the datasheet.

    Any hekp please ?
     
  2. Rocket.Man

    New Member

    Jan 1, 2012
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    I have been experementing with Power Mosfets if they stay ON too long they make lots of heat. If you can set the duty cycle of your pulse so it is ON 10% or less then OFF 90% or less, much less heat is produced.

    [​IMG]
     
  3. kanoun

    Thread Starter Member

    Jan 29, 2015
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    This is basically the case but still have this problem ... Moreover, I'm measuring the temperature as well and it is not more than 30C
     
  4. #12

    Expert

    Nov 30, 2010
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    So many aspects! Is your resistor inductive? Do you have local capacitors on the test jig? Is your current probe defective? Are your grounds generous? Is your IGBT 2 amps better than typical or 2 amps worse than typical? Two amps worse than the minimum guaranteed performance?

    Trying to replicate a professional test requires professional skills and professional equipment.
     
  5. kanoun

    Thread Starter Member

    Jan 29, 2015
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    Many thanks for this reply


    Is your resistor inductive? Yes but what is the problem with this? In fact I did the measurement without the resistance and the results are the same.

    The current probe is not defective since I measured the same current on a resistance

    My IGBT is 2 A less than the output characteristics from the datasheet (I reproduced the Ic-Vc curve and I figured out that I have a 2 A less)
     
  6. #12

    Expert

    Nov 30, 2010
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    1) an inductive resistance can cause a lot of noise at the speed of your pulses.

    2) Two amps less than, "typical" or two amps less than the minimum guaranteed performance?
     
  7. kanoun

    Thread Starter Member

    Jan 29, 2015
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    I'm reproducing the IcVc curves and comparing to the datasheet. 2A less basically
     
  8. #12

    Expert

    Nov 30, 2010
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    If that is a "typical" performance curve there might be nothing wrong. If you refuse to look up the minimum guaranteed performance, I also refuse.
     
  9. kanoun

    Thread Starter Member

    Jan 29, 2015
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    I'm not refusing. Is this information available in the datasheet ?
     
  10. ronv

    AAC Fanatic!

    Nov 12, 2008
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    Last edited: Jan 29, 2015
  11. kanoun

    Thread Starter Member

    Jan 29, 2015
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    I
    I will post a graph from the scope ... Is it possible that the fact that I'm not driving the gate with a gate driver but only a pulse generator lessen the current (the actual gate voltage could be the one of plateau of Meyer)
    One more question the rise time in my signal is not that steep could it explain this as well ?
    I already posted the circuit im using
     
  12. ronv

    AAC Fanatic!

    Nov 12, 2008
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    I'm not sure what curve you are trying to duplicate or where it is different from that curve.
     
  13. kanoun

    Thread Starter Member

    Jan 29, 2015
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    Ic-Vce curves for different vg
     
  14. kanoun

    Thread Starter Member

    Jan 29, 2015
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    The Ic current is 2A LOWER for all Vg when I compare to Ic Vce carac from datasheet
     
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