• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 64 subscribers
  • Views 220 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

TPS53321: TPS53321 efficiency calculation

Alan Chang
Intellectual 2230 points
Part Number: TPS53321
Other Parts Discussed in Thread: TPS62866, TPS62869, TPS54478, TPS62826A

Hi sirs, 

   My customer would like to estimate TPS53321 efficiency, however, only high/low side Rds_on on data sheet. This device is not in Webench. Is there device model for efficiency calculation. Or how much Qg of internal FET for switching rising / falling time estimation.

  • 0
    TI__Guru*** 146780 points

    Hi Alan,

    The efficiency curves are provided in the D/S, so there should not be a reason to calculate anything.  Also, calculations have an error/tolerance factor, which makes them generally less useful that real, measured data.

    But what Vin, Vout, and Iout do you have in your application?  This is an older device.  We have the TPS62866 and TPS62869, as newer 6A devices, for example.

  • 0 in reply to Chris Glaser
    TI__Intellectual 2230 points

    Hi Chris,

       Thanks for your reply, but I need 0.7V out/3A from 5V input, no curve on data sheet. I'm asked to offer efficiency data by calculation, not measurement only. Or BU can give a data based on 0.47uH/4.2mohm inductance, 2 pcs of 22uF MLCC and 1 pc of 560uF/7 mohm ESR condition? Thanks.

     

  • 0 in reply to Alan Chang
    TI__Guru*** 146780 points

    Hi Alan,

    Thank you for providing your application needs.  Do you need to sync to a clock, or have other features that are needed?

    If you must have a calculation for the efficiency, we need to find a newer device which supports this.  Efficiency calculation is not supported with the TPS53321.

    Would the other 2 devices that I mentioned work in your application?  If not, what about the TPS62826A or TPS54478?