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UCC24624: ucc24624

Sangeetha V
Prodigy 30 points
Part Number: UCC24624

Hi,

The IC UC C24624 is getting heated up. The gate signals obtained are different . The VDS waveforms and the drain currents are as shown in the figure. Please suggest a solution for this issue.

  • 0
    TI__Genius 9140 points

    Hi Sangeetha,

    thanks for your interest in UCC24624.

    for the narrow pulse output from one channel of UCC24624, usually it is cause of noise on VSS pin. My suggestion is:

    1.add 47ohm+330pF~1000pF on mosfet Drain-Source pin.

    2. add a a RC on the VSS pin.you can follow below caputured.

  • 0 in reply to David Huang33
    Prodigy 30 points

    Hi David,

    Thank you for the suggestions. Could you please verify point no. 2, does RC is placed on the VSS pin or VD1 pin? in the  given fig.,  an RC is placed at the VD1. Please check and update

  • 0 in reply to Sangeetha V
    TI__Genius 9140 points

    Hi Sangeetha,

    sorry for the mistake. For second item, RC should be add on both VD1 and VD2, not on Vss.

  • 0 in reply to David Huang33
    Prodigy 30 points

    Hi David,

    When I connected RC across the mosfet drain to source my LLC IC got damaged.. what could be the reason?

  • 0 in reply to Sangeetha V
    TI__Genius 9140 points

    Hi Sangeetha,

    do you mean when connecting SR Drain-Source RC cause primary LLC controller damaged? does any other device damage accompany?

    which controller do you used? Is it on the primary or second side?

    you can try to add a smaller RC on SR mosfet first, for example start from 47ohm+47pF, and step by step increase the value of the cap.

    I am wondering whether with a very big RC on the SR cause a short through on the primary side, then high voltage couple to the LLC controller and cause the failure.

    can you share with me the full schematic including both LLC controller and SR circuit?