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PMP40580: What are the specs for the Jewel BCK-50-722D transformer used in this design?

DARIN
Intellectual 385 points
Part Number: PMP40580

Hi,
My application is incredibly similar to the PMP40580 ref design.  I need 5A@12V and 2.78A@54V, but almost the same.  I was so thrilled to have found it.

Wurth is designing a custom transformer for me, but it would be hugely beneficial to know what the primary and leakage inductance are in the Jewel BCK-50-722D that is being used in that design.  The capacitors chosen were based on this for the LLC design.
Can TI provide the spec from the manufacturer (Jewel) for T100 of the PMP40580?

Thank you.

Darin

  • 0
    TI__Prodigy 510 points

    Hi Darin,

        Since the designer has no longer in TI. I just have the briefing info on the transformer. Pin(3-2) : 36 Turns(Lm 500uH, Ls 88uH) ; Pin(6-5) : 3 Turns ; Pin(9-8) 24 Turns ; Pin(13-11) 2 Turns; Pin(14-12) 2 Turns. Core material: FERRITE EE4915 PC40. 
    Please let me know if these parameters can satisfy your needs.

    Regards,

    Richard

  • 0 in reply to Richard Yin
    Intellectual 385 points

    Hi Richard,

    I thought that they satisfied my needs, but I think this could be the wrong transformer.

    If you look at the schematic for the PMP40580, the pin numbers that you listed don't match up.

    But then, the pin numbers on the schematic don't make sense for any transformer.  The bias winding should be on the same side as the primary, among other things.

    The description of the Jewel BCK-50-722D transformer in the BOM is "Transformer, 400uH, 14-pin, TH, EE49", which better matches what you describe (except for showing 400uH vs. your 500uH).

    Any idea how to reconcile these discrepancies?

    Darin

  • 0 in reply to DARIN
    Intellectual 385 points

    Hi Richard,

    Maybe it would be easier if you just emailed the Jewel spec to me.  The custom manufacturer wants to make sure that the impedance matches.  These are their questions:

    Are both secondary windings shorted during the test of leakage inductance?

    What tolerance is preferred for the specified Ls (leakage inductance) as seen by the primary? 

    The Jewel website hasn't been reachable since I started checking several weeks ago.  Maybe the spec sheet has a different link?

    Any extra info that you have would be appreciated.

    Thank you.

    Darin

  • 0 in reply to DARIN
    TI__Prodigy 510 points

    Hi Darin,

        Let me contact with the designer again for the further info you need. Will reply you soon once I got more info on the spec of transformer.

    Thanks!

    Regards,

    Richard

  • 0 in reply to DARIN
    TI__Prodigy 510 points

    Hi Darin,

        It must be some mistake on schematics. Would you pls to leave the mail here that we could discuss more for correct the schematics and Pins of transformer.

    Regards,

    Richard

  • +1 in reply to Richard Yin
    Intellectual 385 points

    Hi Richard,

    My email is dmilton@Airvine.com.  Since I am changing the pinout, I'm okay that the schematic is incorrect.  I just have to be sure that the specifications that you gave above match the part that was installed in your evaluation board.  Wurth electronics also wanted to verify that Jewel tests leakage inductance with the same method that they do.  Thank you.

    Darin