IR 2110 get damaged when connected to trafo

Discussion in 'The Projects Forum' started by iyunxpenxhunx, May 30, 2016.

  1. iyunxpenxhunx

    Thread Starter New Member

    Jan 17, 2016
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    Hi, I'm a newbie here
    I have a project to make an inverter using uC and H-Bridge Mosfet by IR2110 driver and step up the voltage using power trafo.
    Before I connect the circuit to the trafo, the output seems well, and the circuit work well. But when I connect H-Bridge output to trafo, the circuit get damage, actually IR2110.

    I attached my circuit

    Sorry for my bad english
    I really really appreciate for your help
    Thank you

    Note : I increase the bootstrap cap by pararelling 10uF so the bootstrap cap value is 14.7uF
     
  2. HW-nut

    Member

    May 12, 2016
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    It does not look like the design will prevent turning on the high and low side mosfets at the same time. This would destroy the device quickly. This may be occurring during the MPu reset cycle before the I/o is configured. I did not check your specific micro, but it's very common for all of the I/o pins to be on figured as inputs with a soft pull-up after reset. For your design, this would destroy the mosfets. Verify the I/o state after reset on the micro after reset and add some pull-down resistors to the micro outputs as needed.
     
  3. iyunxpenxhunx

    Thread Starter New Member

    Jan 17, 2016
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    I have add some deadtime to prevent turning the Hi and Lo for the same time
    Can you tell me what is the function of pull down resistor to the uC output?
    Thank you for your reply
     
  4. HW-nut

    Member

    May 12, 2016
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    The MPU will go through cycle after power-on for a short time (<10 msec, depends on micro). During the reset cycle, the MPU I/O will be configured for the reset state which is common to be an input with a soft internal pull-up. This causes the I/O signals to go high causing the mosfet damage. The pull-down resistors terminate the inputs low during reset which keeps all the outputs low.
     
  5. tcmtech

    Well-Known Member

    Nov 4, 2013
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    For starters, I see a bunch of stuff in your circuit that doesn't need to be there when compared toe the IR2110 -2113 specs sheets. :rolleyes:

    U1,U2, D1, D2, D4, D5, R5 - R8 are not needed.

    For normal H-bridge operation (H in) pin 10 of one IC can be tied to (L in) pin 12 of the other to give you your two controlling inputs.

    The way you have int now U1 and U2 can conspire to have the H out and Lout on at the same time in the same IC thus likely producing the killer shoot through condition while switching.
     
  6. Lestraveled

    Well-Known Member

    May 19, 2014
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    A while back I had a similar problem and it turned out to be ringing due to trace inductance would drive the VS pin so far negative that it would destroy the high side driver chip. Here is an app note that explains it and the fix. See section 2.4, 4.4 and figure 18.
     
  7. iyunxpenxhunx

    Thread Starter New Member

    Jan 17, 2016
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    So where should I put the pulldown resistor? Is is in the output (PB0, PB1 and PB3) or in the input (but there is no input for uC though)?
    And what is the value of pulldown resistor?

    thankyou
     
  8. iyunxpenxhunx

    Thread Starter New Member

    Jan 17, 2016
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    I need U1 and U2 to produce SPWM for each leg, so that it can produce half SPWM
    D1-D4 need for increasing deadtime, due to App note AN-978
    R5-R8 as pulldown resistor for unwanted noise which is affecting to gate being high
    Correct me if I was wrong
     
  9. iyunxpenxhunx

    Thread Starter New Member

    Jan 17, 2016
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    Thank you, I'll read it
    Hope that I can fix this problem
     
  10. iyunxpenxhunx

    Thread Starter New Member

    Jan 17, 2016
    17
    0
    Thank you, I'll read it
    Hope that I can fix this problem
     
  11. tcmtech

    Well-Known Member

    Nov 4, 2013
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    Yes, you are wrong in the sense of over complicating the circuit for no logical reason. Given the totem pole configuration and switching speed of the IR2110's output stages the diodes are doing nothing for dead time and they already pull down the gates of the devices thus making the pull-down resistors R5 - R8 pointless.

    Also if the proper programing was used there would be no need for having to use U1 and U2 to add the PWM signal froma third source to the outputs to which as the IR2110 driver IC's are designed both the alternate upper and lower switching devices in the H-bridge can be PWM'ed together without problems meaning as I pointed out before Hin of one IC can be tied to Lin of the other and such thus enabling both switching devices that are on at the same time to handle the PWM work together.
     
  12. Lestraveled

    Well-Known Member

    May 19, 2014
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    @tcmtech
    I don't get what you are trying to say. Maybe you could be more specific. I have used the diode in parallel with a resistor gate circuit. It slows the turn on time and reduces the turn off time, which increases dead time. This a good thing to prevent shoot through. So, what is your argument again. (Tis a puzzlement.)
     
  13. ronv

    AAC Fanatic!

    Nov 12, 2008
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    It might also be worth a couple of decoupling caps on the 12 volts close to the drivers.
     
  14. HW-nut

    Member

    May 12, 2016
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    The maximum value can be calculated by dividing the low threshold voltage by the soft pull-up current. Typically, 10k is fine.
     
  15. ronv

    AAC Fanatic!

    Nov 12, 2008
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    One more question along the lines @Lestraveled suggested.
    How far away from the drives are the FETs? Keep the distance short from driver to gate and source to driver.
     
  16. tcmtech

    Well-Known Member

    Nov 4, 2013
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    Although that will create a time delay for the turn-on and turn-off points it sort of defeats the whole concept of what the High/low side driver IC's are for which is to have the fastest most efficient switching possible.

    Also given that the OP is using a microcontroller of some sort all the needed dead time and other PWM related work should be easily handled in the coding and not need to rely on odd configurations of additional external components between the uC and driver IC's or after the driver IC's to make up for bad coding and or unrealistic operating conditions.

    So far the OP has given no information about what base frequency he is using or what PWM frequency either which for all we know he is trying to generate a 50 - 60 HZ signal using multi-hundred KHz PWM frequency putting his odd configuration of additional components well beyond their viable working ranges and ability to function as wanted.
     
  17. HW-nut

    Member

    May 12, 2016
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    Have you tried adding pull-down resistors to the MPU outputs?
     
  18. iyunxpenxhunx

    Thread Starter New Member

    Jan 17, 2016
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    I use U1 and U2 refer to tahmid blog http://tahmidmc.blogspot.co.id/2013/02/generation-of-sine-wave-without-eccp_16.html
    and when I use a scope to see the signal, and it works

    I use 10kHz carrier signal
     
  19. iyunxpenxhunx

    Thread Starter New Member

    Jan 17, 2016
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    Not yet
    Because I have to re-doing the PCB to put the pulldown resistor
    I'll do it as soon as possible
     
  20. iyunxpenxhunx

    Thread Starter New Member

    Jan 17, 2016
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    I use a jumper, because I made each circuit block by block
    Why does the distance from driver to gate affect the circuit? I read AN-978, and it said that it will add a parasitic element, but I dont understand what parasitic element is

    Thank you
     
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