• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 63 subscribers
  • Views 303 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

TPS53353 Rds(on) datasheet contradiction?

Ping Yao
Prodigy 20 points
Other Parts Discussed in Thread: TPS53353

Hello,

this is my first post, and fairly new to DC-DC design.  It seems there's a contradiction in the TPS53353 datasheet.  On page 3, in the ELECTRICAL CHARACTERISTICS - INTERNET MOSFETs, the low-side MOSFET on-resistance is defined as 2.2mOhm.  However, on page 21, in the External Component Selection - 6. CHOOSE THE OVERCURRENT SETTING RESISTOR, it's recommending using Rds(on) value of 1.6mOhm for overcurrent level of 20A.

am I misunderstanding something?

thank you in advance for your help.

Ping

  • 0
    TI__Mastermind 49370 points

    Hi Ping,

    The Rdson for OCP usually only include the silicon Rdson, while the Rdson for power dissipation will include the Rdson and the package parasitics(like bonding wires etc). This is one of the difference. Also the ITRIP(current to set OCP) is temperature compensated. So equivalently the Rdson variation will not be affected by temperature in OCP setting. I attached spreadsheet of TPS53353 for your reference.

    Thanks,

    Nancy

    7345.TPS53353 Design Spreadsheet.xls

     

     

  • 0 in reply to Nancy Zhang
    Prodigy 20 points

    Hello Nancy,

    thank you very much for your quick response and help.  It seems strange that this information is not well explained in the datasheet.  Nonetheless, you answer explains the difference.

    Ping