IGBT driver

Discussion in 'The Projects Forum' started by Questioner1.0, Jul 20, 2013.

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  1. Questioner1.0

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    Jul 20, 2013
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    Hi guys,
    So I have a project that I'm working on using a micro-controller to give input to an IGBT driver. The driver that I am using is the MC33153.
    My question is why am I only getting a mV signal from the output pin?
    I'm providing about 16V to the Vcc input and connecting Vee and the kelvin gnd inputs to ground. I'm also providing a TTL square wave to the input pin.
     
  2. shortbus

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    Adding a schematic makes it easier to get help.
     
  3. Questioner1.0

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    heres the schematic for how I have the driver connected.
     
  4. shortbus

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    Having never used this driver, this will be a guess. I don't see a way for it to work with out using all of the connections. You can't pick and chose which connections of an IC to use.

    If you don't want or need the current sense feature of this driver you will have to follow the steps on page #11 of the data sheet. For most situations the data sheet has the solution. Or chose another driver.

    http://www.google.com/url?sa=t&rct=...n1LeFlJkQEz_OSmn14HWvmg&bvm=bv.49478099,d.aWc
     
  5. Questioner1.0

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    Jul 20, 2013
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    ok so I'm still not getting anything higher than 3 mV out when I put 5 V in. So two questions really, on the datasheet where it says about the logic input threshold voltages for the low state and high state values that are given, does the LS voltage need to be below that value and the HS voltage above?
    The second question is, what is "kelvin ground"? I haven't come across it in my electronics classes and what I've been able to find on the internet wasn't making sense to me.

    Thank you for pointing out that there was actually more to the datasheet than I'd seen. For some reason I did not see that there were more pages after the graphs.
     
  6. Ron H

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    The Kelvin ground needs to connect directly to the emitter of the IGBT with a dedicated trace. Do not simply connect it to global ground.IGBTs generally conduct high current when they turn on. This current can generate significant voltage drop across a poorly designed ground network. The purpose of the Kelvin ground is to measure the voltage at the emitter, instead of at some random point in the ground network.

    Have you connected pins 1 and 8 to ground?
    You also need a 100nF capacitor between the Vcc and Vee pins, as close to the IC as possible.

    EDIT: Connect pin 1 to pin 2, not to ground.
     
    Last edited: Jul 22, 2013
  7. Questioner1.0

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    Jul 20, 2013
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    How do you do that? Do you just connect them with a wire? And why does the Kelvin ground need to be measured at the emitter?
    Thanks for the answers I really appreciated all the help :D
     
  8. Ron H

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    If you have this built on a breadboard, use a wire. On a PC board, use a trace.
    Did you read the hot link I posted?

    EDIT: Connect pin 1 to pin 2, instead of to ground as I previously recommended.
     
    Last edited: Jul 22, 2013
  9. shortbus

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    Some IGBTs have the sense resistor built into them with a connection point for it.
     
  10. Questioner1.0

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    Jul 20, 2013
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    so here is the new schematic of how its connected using all of your sugestions, however, its still not working. The input going in on pin 4 has two states with the low being about 100 mV and the high being about 4 V. I'm still getting a constant output of about 3 mV. I can't figure out why its doing this, I'm seriously thinking about finding a new driver.
     
  11. Ron H

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    You still need a ground connection to the emitter. I guess I didn't make that clear.
     
  12. Questioner1.0

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    Jul 20, 2013
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    oh I forgot to put that connection in my schematic, but its still doing the same thing
     
  13. Ron H

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    Can you post a link to the IGBT datasheet?
     
  14. Questioner1.0

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  15. Ron H

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    Stupid question: Do you have the low side of your 16V supply connected to circuit ground?
     
  16. Questioner1.0

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    Yes I do, its kind of an odd supply though. It has V+ and V- but the V- and the gnd on the supply are sitting at the same place so there's only an option of getting the +16
     
  17. Ron H

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    Have you considered that your driver may be defective?
     
  18. Questioner1.0

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    yes so I tried four different ones they all gave me the same thing. I really need to be able to drive that IGBT and from what I've read, the best way to do that is to use an IGBT driver but I'm not sure how to find one that will work since my first choice is not working. Do you have any advice on that?
     
  19. Ron H

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    You either have a wiring error, or we have misinterpreted the datasheet.
    Post a picture of your breadboard, with enough resolution to allow us to compare it with your schematic.
     
  20. Questioner1.0

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    Jul 20, 2013
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    The green wires are gnd, the purple wire on the left is the signal coming in and the purple wire on the right is Vcc.
     
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