• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Subscribers 63 subscribers
  • Views 348 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.

TPS659413EVM: Series resistor for VSYS_SENSE pin

Andrew Xiong
Expert 5470 points

Part Number: TPS659413EVM

Hi,

In the EVM design, the series resistors R20 and R21 are used at the VSYS_SENSE pin. Both of them are 240ohm. My customer has a question that if those two resistors can be replaced by one 480ohm resistor? Is there any special consideration here to use series resistors?

Thanks,

Andrew

  • 0
    TI__Expert 5470 points

    Hi team,

    Could anyone please help with it?

    Thanks,

    Andrew

  • 0 in reply to Andrew Xiong
    TI__Mastermind 48881 points

    Hi, Andrew,

      Yes, those two resistors can be replaced by one 480ohm resistor with power consumption met. The major consideration is descried below:

      VSYS_SENSE pin serves two functions. It supplies internal 3x charge pump and VSYS over voltage comparator among few other things.

      These resistors can't be too high resistor values, because:

      1) It causes additional over voltage detection delays impairing the protection function.

      2) It causes too large voltage drop, which can potentially lead to internal supply rail to collapse/to become too noisy.

  • 0 in reply to Phil Yi
    TI__Expert 5470 points

    Hi Phil,

    Thanks for your reply. But sorry I'm a little confused about it. Do you mean that the 1*480ohm resistor will bring additional over voltage detection delays and larger voltage drop than 2*240ohm?

    I'm afraid I didn't understand it.

    Regards,

    Andrew

  • 0 in reply to Andrew Xiong
    TI__Mastermind 48881 points

    Hi, Andrew,

      1*480ohm resistor can replace 2*240ohm and no difference from point of view for voltage detection delays and voltage drop. You may need to use 1*480ohm 0603 size resistor to replace 2*240ohm 0402 size resistor when considerate the power consumption.