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UCC28630: Can UCC28630 match with IPFC UCC28070 circuit?

Part Number: UCC28630
Other Parts Discussed in Thread: UCC28070, UCC28633, UCC28632, UCC28631, UCC28063, UCC28180

Hi all,

I am the newbie of the power circuit design, since I need to design are 180W flyback SMPS (30V 6A) with fulfill the current energy level standard (COC Tier1 and DOE VI) , may I know  UCC28630 and UCC28070 can combine to use together? In addition, I just check the UCC28070 evm datasheet, it seems no any circuit to minimize current consumption of  the UCC28070 when the smps is idle, did any reference document mention about this? thanks so much for the help!

Best Regard.


  • Simon,

    The UCC28630/1/2/3 family of Flyback controllers have slightly different functionality, as shown in the Device Comparison Table on page 4 of the datasheet.

    Since both UCC28630 and UCC28633 have an intenral X-cap discharge feature, the HV pin must be connected to the AC side of the diode bridge, they cannot be connected to the DC bulk cap. If the HV pin is connected to the AC side, then they can be used with a PFC front-end.

    For the UCC28631 & UCC28632, there is no X-cap discharge function, so the HV pin can be connected to either AC or DC. This flexibility probably makes them more suitable to run from a PFC front-end.

    Regarding the UCC28070 PFC controller, I will get one of my colleagues who is more familiar with this device to answer your questions.

  • Hi Simon

    The UCC28070 is an interleaved two phase CCM PFC controller and is more suited to higher power levels.

    Interleaved PFC is useful for low height profile applications such as Digital TVs. For 180W we would recommend the UCC28063 Interleaved Transition mode PFC controller.

    The UCC28180 is a single phase CCM PFC controller which is in an 8 pin device and offers good PFC performance.

    None of the controllers have a low power mode although the UCC28063 has a feature to allow single phase operation to improve efficiency at lighter loads.


  • Dear Bernard, Peter,

    Thanks all your help to suggestion, I will choose UCC28631 and UCC28063 to form my smps, now I was draft the schematic in attachment, would you please help me to check is it correct or not?

    Beside, from the schematic, if I want to modify the output voltage and current, which side I need to tune?

    Thanks very much for the help!180W_power_smps.pdf

  • Hi Simon,

    Our office is closed until the 4th of January, is it ok for us to review the schematic then?


  • Simon,

    I will comment on the UCC28631 Flyback portion of the schematic, and one of my colleagues will respond regarding the UCC28063 boost PFC portion.

    - R16 connecting to HV pin should be 2 resistors in series since most SMT resistors are limited to 200 V max rating.
    - For the VSENSE pin network, there need to be an extra resistor in series between the common-cathode of D7 and the junction of R24/R25/R26/R27 - this should be 3k7, referred to as Rp in the datasheet.
    - C20 connection seems wrong, this is putting a capacitor in series with the secondary winding, that won't work

    To help with the power stage design and choice of the critical parameter values (transformer magnetising inductance Lp, turns ratio Np/Ns, current resistor value R20), you can use the Excel design calculator on the UCC28631 product page, under the "Tools & Software" tab:

  • Dear Bernard,

    Thanks so much your detail explanation and suggestion, I will follow yours to design the smps, thanks you!

    Best Regards.


  • Hello Simon,

    The schematic for the UCC28063 section looks correct. Please use the calculator tool to calculate the component values. The calculator is located here: