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UCC28083: UCC28083D

PSENGINEER Intelux
Intellectual 260 points
Part Number: UCC28083

PROJECT - 1KW PUSH PULL DC DC CONVERTER

VIN=48V ,VOUT=350V POUT=1000W

THERE IS MOSFET THERMAL ISSUES i.e MOSFET REACHES 100 DEGREE CELSIUS IN 1 MIN AT 400W 

AND THERE IS HUMMING NOISE AT 659 WATT POUT

I AM ATTACHING WAVEFORMS AT 659W  IS THERE ANY ISSUE WITH DESIGN

TRANSFORMER=ETD49 ,P1:S:P2 =(7:63:63) Lprimary=175uH

SWITCHING FREQUENCY= 120khZ

  • 0
    TI__Mastermind 34465 points

    This is a repeat of the following post

    https://e2e.ti.com/support/power-management/f/196/t/877132

    I am therefore closing this post and will answer your question in the above referenced post.

    Regards

    John

  • 0
    TI__Mastermind 34465 points

    It looks like both FETS are on simultaneously at the transition points.
    The gate signals seem to be turning off too slow.
    This is causing the transformer to saturate and the high peak currents are the source of the audible noise

    I suggest you re-evaluate your driver design to the FETs and speed up the turn on and turn off gate drive signals.

    Also check the transformer design.
    Make sure the core is designed to support the applied Volts-Seconds applied for this application.
    Make sure the maximum flux density is not exceeded.
    A transformer manufacturer will help you with this.

    And also ensure the winding is fitting properly on the bobbin and either encapsulated or vacuum varnished.

    There will always be some low level audible noise present but it should be continuous and low level.

    Regards

    John