This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

  • TI Thinks Resolved

LM25085: LM25085

Expert 1070 points

Part Number: LM25085

Hello,

It  appears to me that the Efficiency of the LM25085 is poor…

 Taken from WEBENCH,efficiency is around 70% at 8A.

 We can’t  proceed with such low performance.

 Please advise.

Thanks

  • Hello Hen,

    Can you share the specification you are designing to?

    Thanks.

    David.

  • Expert 1070 points

    In reply to David Baba:

    Hi

    The application is small cell base station.

    The customer run WEBENCH for the part and got 70% efficiency at 8A,this is poor , why?

    He is on the schematic and need fast response other wise he chose competitor.

    I suggested him also to test the LM3152, what he need is ,

    input: 30v

    output: 3.3v

    Iout= 10A

    Thanks 

  • In reply to Hen:

    Hello Hen,

    Are you saying that customer got 70% in WB? Is it possible you can share the WB design? When I run WB I get an efficiency above 90%?

    If you are referring the bench performance, please can you share schematic and also have customer scope switch node when running at full load to see if the design is stable?

    Thanks.

    David.

  • Expert 1070 points

    In reply to David Baba:

    Hi
    I also run WEBENCH , I got ~70% ! Please advise

    webench.ti.com/.../webench5.cgi
  • In reply to Hen:

    Hello Hen,


    The reasons is the Diode forward voltage drop is 1V, you can select an alternative part and make a custom part with a VF of 0.5V and the efficiency goes up to around 81%.

    It might be worth considering a synchronous buck controller if you need efficiency closer to 90%?

    hope this helps?

    David.

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.