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UCC28019A: UCC28019A

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Prodigy 40 points
Part Number: UCC28019A

Tool/software:

Hello all,

We are creating a PFC circuit that maintains a 19.2V~24V AC input voltage with an output voltage of 36V.  

But Excessive current flows during PFC startup and momentary breakdown recovery.（Please check the attached documents.）

I think that the cause is coil saturation or phase compensation design.

If you have any findings from looking at any waveforms, we would like you to share them with us.

TI問い合わせ.pdfUCC28019A Design Calculator_標準電源.xls

  • 0
    TI__Mastermind 40550 points

    Hello Sir, 

    The waveforms in the .pdf file show high peaks because the inductor (coil) is saturating.  The core is powdered metal alloy, so it is a soft saturation, but it does allow high peak currents. 

    In the Design Calculator file, in the Calculations tab at cell C94, you have 4mR for the current-sense resistor value.  The Calculator recommends 19mR.  
    Entering 18mR at C94 will satisfy the tool and allow the current limit to cut down the peak inductor currents and reduce the saturation level. 

    I recommend to increase the value of Rsense in your PFC circuit.  

    Regards,
    Ulrich