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UCC28063: Circuit Design and Precautions

Part Number: UCC28063

Hi 

My customer is designing a 400W SMPS.

PFC Block (UCC29063)
1) Is there any problem when the VINAC voltage is repeatedly turned on and off while the VCC voltage is applied?

2) In the attached schemetic,No separate driver IC was used. Is there a problem?

3) It will be applied to nuclear power plants. What should I keep in mind when using it?

SCH-MMIS-190808(TI_24V).pdf

  • Hello,

    The UCC28063 does have brownout protection.  When VINAC drops below 1.39V peak it will enter brownout and the controller will stop switching. 

    If VDD is regulated by a separate bias the gate driver switching will stop until VINAC peak is greater than 2V.  Section explains in detail how the UCC28063 will control the interleaved boost stage to recover from a brownout event.

    If you need the circuit to continue to operate during multiple brownout conditions.  I would recommend that you size the output boost capacitor (Cout) to service the longest brownout time.  Equation 31 in the data sheet describes how to size Cout based on one line cycle dropout.  If you want to increase this you can replace fLINE by 1/tdead.   Where tdead is the longest time between AC input turn on and turn off.

    Regards,