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ADuM3223 issue

Dear sir,

I have some issue about ADuM3223 as attached file.

Is the ADuM3223 can driver two MOSFET by Voa or Vob?

If not connect resistance to GND, Is Voa has output voltage?

please help to answer for me, Many Thanks!!!

  • Hello Jackal,

    The ADuM3223 is able to drive multiple MOSFET gates as you have shown, provided the MOSFETs are balanced well, and are able to be run in parallel. Common causes of inbalance include differences in inductances of the drain-source connections of the parallel FETs, RDson differences, etc.

    The VOA and VOB pins of the ADuM3223 are push-pull. The resistors from VOA to GNDA and VOB to GNDB are usually placed in order to pull the gate low in case of loss of communication with the gate driver.

    After the system is damaged, does Channel A on the ADuM3223 still function?

    Has this system been tested with another board? It is interesting that the failure is always on the same FET, but with only two cases, we don't have enough data to tell for sure what is going on.


  • Hello Jackal,

    Looking again at the schematic, I noticed the D6 and D3 diodes. In your system, do you guarantee that the average current is flowing from W to D across the load? If not, is it possible that D6 is preventing current flow and the PLP2 MOSFET is over-voltaged?

    If so, increasing the RCD snubber (R25, R26, D11, C26) size might help reduce over-voltage.

    Are the D6 and D3 diodes required in your design?


  • Dear RSchnell,

    I know if driver multiple MOSFET and RDson is different. But if MOSFET receive max current can cover continua current, I think that is Okay.

    As customer reply information:

    After the system is damaged, the VAO to GND and VOB to GND still have 5V voltage.

    Could you kindly tell me what mean is Channel A? is the VDDA or VOA?

    This system do not test with another board.

    Best Regards,

    Jackal Teng

  • Dear RSchnell,

    The D6 and D3 function is avoid reverse current.

    So, I can try to get rid of D6 and D3 to test.

    If any new question, I will reply you first and please kindly help suggestion me, thanks!!!

    Best Regards,

    Jackal Teng

  • Hello Jackal,

    Channel A refers to VDDA, VOA, and GNDA.

    Channel B refers to VDDB, VOB, and GNDB.


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