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  1. #21
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    Re: MOSFET Gets Hot in H Bridge

    Okay, increased the C1, C4 capacitors to 22uF but no change in output.

    I am using 50% duty PWM. Should I increase the duty to say 90% to get high output voltage of say +22V or +24V?



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  2. #22
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    Re: MOSFET Gets Hot in H Bridge

    Hi,

    As already said: high duty cycle makes things worse.

    Show us scope pictures (HIN, 12V directly at the driver, highside_out, 24V supply) and a photo of your circuit, including the scope connections.

    Klaus
    Please don´t contact me via PM, because there is no time to respond to them. No friend requests. Thank you.



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  3. #23
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    Re: MOSFET Gets Hot in H Bridge

    Here is the simulation output. I have not yet built the hardware.

    - - - Updated - - -

    Updated file. VSx probes added. See the graphs and tell me how to fix the high-side voltage issue.

    - - - Updated - - -

    Edit 2:

    Only getting correct output when dual supply is used for IR2112.

    Refer INV-6.2.pdf

    Can't the issue be solved without using dual supply for IR2112?

    - - - Updated - - -

    My conclusion with the circuit analaysis is that the voltage at COM pin of IR2112 should be equal to the GND voltage of Full-Bridge. So, I used -24V.0V for IR2112 COM pin and th eoutput is okay but will the high-side mosfets handle 60V of HOx signals for IRFP064V?

    Also, the VSx voltage should swing between +24V and -24V same as Load.
    Last edited by baileychic; 23rd August 2019 at 08:04.



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  4. #24
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    Re: MOSFET Gets Hot in H Bridge

    I replaced the Mosfets to IRFP250N.

    For PWM signal > 50 kHz the output signal is getting distorted and also the HOx and LOx signals. What changes are needed to the circuit to get clean output for 300 kHz PWM?



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