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UCC28951: Realization of ACDC converter

Dice-K
Mastermind 7480 points
Part Number: UCC28951
Other Parts Discussed in Thread: UCC28070, , UCC28950, UCC28070A

Hi support team,

I am looking for a 2-output ACDC converter with the following specifications.
Can this be achieved with this IC?
Please let me know if there is another suitable IC.

ACDC converter specifications
・AC Input Voltage Range: 85 to 264V
・DC Output 1: 60V, 10A
・DC Output 2: 12V, 30A
・Isolated : Yes
・Application: Large capacity charger

Regards,
Dice-K

  • +1
    TI__Guru* 86266 points

    Hello,

    This power range is 960 W.  You will need a PFC pre-regulator at this power level.  You may consider using the UCC28070 to power factor correct (PFC) the input current and convert the AC line voltage to DC.  This is typically 85 to 265 V AC in to 390 V DC.

    I found this 1.2 kW reference design that is close to your design needs.

    https://www.ti.com/tool/PR779

    If you want to do a customer design with the UCC28070 you can always use the Webench design tool that can be found at the following link. If you have questions regarding the UCC28070 please repost with the UCC28070 in the title so the appropriate applications engineer can help you.

    In regards to the UCC28951 I reviewed the reference design library and did not find a multi output design.  They were all single output designs.

    https://www.ti.com/product/UCC28950?keyMatch=UCC28950&tisearch=search-everything&usecase=GPN#reference-designs

    To help distribute the power better you might consider designing two separate FSFB converters for each output. The following link will get you to a UCC28950 600 W evaluation module that steps down 390 V to 12V 50A.  This might be a starting point for both your designs.

     https://www.ti.com/tool/UCC27714EVM-551

    To achieve 60 V 600W you would have to change the output capacitor and SRs.  The following link will bring you to a Webench design tool that can help with that process.

    Just search for Webench on this page.

    https://www.ti.com/product/UCC28951?keyMatch=UCC28951&tisearch=search-everything&usecase=GPN#design-development

    To optimize it for the 12 V 30A output you can use the Webench tool.

    If you want to dig in deeper on how to design with the FSFB.  The following link will bring you to an application note that you may find useful to help you with your design.

    Please note the application note uses the UCC28950, however, it works with the UCC28951 as well.  The UCC28951 just allows for slightly more duty cycle.  Parametrically the devices are 99% equivalent. 

    https://www.ti.com/lit/an/slua560c/slua560c.pdf

    Regards,

  • 0 in reply to Mike O'
    Mastermind 7480 points

    Hi Mike,
    Thank you for your reply.

    Does that mean that UCC28070A or UCC28070 generate DC390V, and UCC28951 or UCC28950 in the latter stage generate 60V and 12V?
    Do I need two UCC2895x?
    Which device is used for isolation?

    Sorry for the rudimentary question.

    Best regards,
    Dice-K

  • +1 in reply to Dice-K
    TI__Guru* 86266 points

    Hello,

    Yes the UCC28070/A devices will be used to power factor correct the input current and generate the 390 V DC output.

    If you build two PSFB power stages you will require two UCC28950 or UCC28951 PSFB controllers.

    Regards,