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UCC28730: vs. UCC28710 current limiting

Part Number: UCC28730
Other Parts Discussed in Thread: UCC28710, , UCC28711

Team,

Is there a difference in the current limiting capability of UCC28730 vs. UCC28710?

It looks like the parametric comparison table calls out an additional current limiting feature in '730, but when I compare the datasheets I don't see a difference in the start-up current limiting capability.

Thank you,

-Kevin 

  • Also can you please advise on the differences between UCC28710DR / '720DR / '730DR? They look p2p drop-in.

    What are the considerations if customer wants to multisource all 3 parts in the same flyback application? 

  • Kevin,

    The parts you mentioned are p2p compatible but there are notable functional differences between them that are found in the data sheets and ther3efore, they are not considered drop in replacements. I think your questions about current differences can be seen here, as summarized in the table below:

    Regards,

    Steve M

  • Hi Steve,

    Agreed with your comments.

    Customer is looking to dual source UCC28710 and UCC28711 by leaving pin 3 on both devices as open (floating).

    1. The cable compensation for both devices would be 0mV, correct?

    2. Any concerns with running '710 or '711 with pin 3 floating? 

    3. Do I have it correct that UCC28710 has internal thermal shutdown (165C), while UCC28711 with no external NTC would have no thermal shutdown protection? Or do both devices have internal thermal shutdown (even w/ no NTC populated)? 

    Thank you!

    -Kevin 

  • Hi Kevin,

    Thank you for the reply.

    Yes both the devices UCC28710 (CBC) and UCC28711 (NTC & CBC) can be used by leaving pin 3 floating.

    The following table shows the effect of CBC pin on Vs regulating level by leaving it open or keeping it shorted to ground.

    1. So leaving it open should be ok and should have minimal impact on Vs regulation levels.

    2. CBC is used in battery charging applications to improve efficiency. This pin can be left floating.

    3. Both devices (UCC28710/11) can operate with a maximum 150 C and has a typical thermal shutdown of 165C.  The thermal shutdowns typical range would be roughly +/- 15 degrees as an estimation based on these limits. The UCC28711 has an NTC function if you need a more accurate device thermal shutdown.

    Please let us know if you have additional questions.

    Regards,

    Harish