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Gate-Driver ADUM4221

Category: Hardware
Product Number: ADUM4221

Hello,

I'm inquiring about the ADUM4221 Gate Driver. I've performed a simulation in LTspice for a half-bridge power electronics application,

but I'm encountering issues where I can't effectively control the high-side MOSFET.

Do you have any example circuits or resources available for the ADUM4221 that I could reference?

My objective is to conduct the simulation without the use of a bootstrap circuit, as I require an isolated gate driver for this purpose.

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  • Hi Patty,

    Thanks for your interest in using the ADuM4221. I can see that your supplies V1 and V2 are referenced to common GND which cause the issue. You should reference your V1 to GNDA (MW_O) so that your high-side FET will see the full 12V gate driver voltage. Same as with V2, the ground connection should be connected to GNDB or MW_U.

    I'm not sure if your are aware of this, but there we example of basic circuit of each of the part if you navigate to your LTspice folder --> example --> Applications as shown below.

    Let me know if you require further assistance.

    Best regards,

    Jefferson

  • Dear Jefferson,

    I want to express my gratitude for your prompt response and the valuable recommendation you provided. I made adjustments to my LTspice circuit, and the simulation now functions significantly better. This has enabled me to successfully control the high-side MOSFET.

    I also managed to locate example circuits within the data path, but I am currently using the Gate-Driver as depicted in the attached images.

    However I am using the Gate-Driver in the following as shown in the pictures: 

    However, I noticed in the datasheet for the ADUM4221, they illustrate a bootstrap circuit. Is this bootstrap circuit necessary for controlling the high-side MOSFETs, or can I achieve the same control of the half-bridges as shown in my LTspice circuit?


    I've included the datasheet circuit for your reference. My ultimate goal is to control a full-bridge circuit composed of these half-bridges.

    Thank you once again for your assistance.

    Sincerly,
    Tahir 

  • Hello Tahir,

    Great to read that your circuit is already working. Just take note of the GNDx connections in your actual implementations. Slight smile

    For the bootstrap recommendation - it is just a recommendation if you like to power the secondary side of the gate driver with a single power supply (VDDB from Figure 38). 

    However, if you have means to provide an isolated power supplies for the high-side gate drivers separately - this is absolutely okay (same as with the LTspice circuit you provided).

    Let me know other concerns you have and I'm happy to help.

    Best regards,

    Jefferson

  • Hello Jefforson, 

    I have one last question. I am using this Gate-Drive for the STP65N150M9  N-Channel MOSFET. 
    Do you see any problem for using this Gate-Driver for this MOSFET type. 
    The MOSFET has a total gate charge of 32 nC.

    Best regards, 

    Tahir  

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