• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Subscribers 64 subscribers
  • Views 1220 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.

TPS2553 Current limit set to 100 mA

Mads Holmer81
Prodigy 70 points
Other Parts Discussed in Thread: TPS2553

Hi,

I am using the TPS2553, an want to limit the current to nom. 100 mA.

By the formulars this result in a 267k resistor

But the data specify RILIM to max 232 kΩ.

Is there something I can do ensure stability ? what are the failure mode ?

Suggest similar parts ?

Thanks in advance

/Mads

  • 0
    TI__Genius 15780 points

    Hi Mads,

    This USB switch falls under the Power Interface forum.  I will go ahead and move this post.

    Thanks,

    Alek Kaknevicius

  • 0 in reply to Aleksandras_Kaknevicius
    TI__Mastermind 42795 points

    Normally, the design requirement will be a minimum or maximum to account for parameter variations. Are you sure you need 100mA nominal or do you need 100mA maximum or 100mA minimum?

    The direct to VIN provides 100mA maximum including tolerance and the 232kohm resistor will provivde 100mA minimum including tolerance. Issues to expect when going beyond the recommended resistor values are some loss of accuracy but we do not have any characterization data for the 267kohm resistor.

    Other devices to consider are hot swap devices with an external sense resistor. These types of devices rely on sensing of the small voltage drop across the sense resistor to current limit.

  • 0 in reply to Eric Wright
    Prodigy 70 points

    Hi Eric,

    Thank you for the respons.

    I need a minimum of 75 mA, over temperature range, component variation etc. and want to keep the maximum as low as possible to protect the power supply.

    With direct to VIN the Current-limit threshold can i worst case be 50 mA according to spec. and that is to low.

    I will go with a value ~249 kohm, that should leave a good margin.