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LM5023: LM5023 have any derived part for use?

Liu Rob
Prodigy 70 points
Part Number: LM5023
Other Parts Discussed in Thread: UCC28600, UCC28C43, UCC2894

Does LM5023 have any derived  part for use? The maxium frequency for LM5023 is 130KHZ, which constraints power supply's size.I like QR mode,but i wish the frequency is up to 200KHZ or more,which will make power supply smaller and compact. Any solution?

  • 0
    TI__Expert 7395 points

    Liu Rob,

    Thank you for your interest in TI here.

    Great question. LM5023 and Ucc28600 are limited to that frequency range to make it easier to pass EMI restrictions.

    Have you looked at using a PWM controller like ucc28c43? Depending on what you're doing that controller goes to 1-MHz but is not QR or valley switching like LM5023.

    Alternatively, you could look at ucc2894 as active clamp:

    That part free runs at 200kHz but you can sync it to higher.

    Could you describe your application and its requirements so that we could better assist?

    Regards

    John

  • 0 in reply to John Stevens
    Prodigy 70 points

    John

    QR mode make a compromise between EMI ,performance and cost.Another advantage of QR mode is in light load condition.The frequecey becomes lower to make the converter more efficiency.UCC28C43,UCC2894 are constant fequrency IC.I use the controller to design dcdc converter. Did TI modify LM5023 for some special custmers before? I indeed find an contoller IC look like LM5023,silk mark changed, PIN TO  PIN compatible,but frequecy is up to 200KHZ or more. I donnot know how to get such an IC

  • 0 in reply to Liu Rob
    TI__Expert 7395 points
    Liu Rob,

    is this for an external power supply like a mobile charger, adapter, where you need to meet CoC/DoE efficiency and standby power requirements?

    Regards,
    John
  • 0 in reply to John Stevens
    Prodigy 70 points
    John,
    Small size DCDC converter,such as brick type dcdc.I care about EMI performance and power density.Higher frequecny is perferred.Did TI modify LM5023 before? How do i get it?
  • 0 in reply to Liu Rob
    TI__Expert 7395 points

    Liu Rob,

    I don't know of any modification to the LM5023 for higher frequency.

    Could you provide the following information and I could search for a reference design for you across all our power products?:

    Input voltage min and max

    Vout

    Maximum continuous current.

    Regards,

    John