• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 62 subscribers
  • Views 106 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.

LM3481: UVLO resistance value.

Kengo.Y
Guru 10625 points
Part Number: LM3481

Hi team,

I'd like to know how to set resistance value when UVLO does not use.
According to the datasheet, it selects greater than 100kohm and the same value for R8 and R7.
So, does it need a diode if it exceeds Vin=12V?

Sincerely.
Kengo.

  • +1
    TI__Guru 60235 points

    Hello Kengo,

    This depends on the rest of the system. If you are using a digital signal for controlling UVLO, you do not need the resistor divider.

    If you want the converter to start without any digital signal applied to UVLO, you need to keep the resistors in the same ballpark and above 100 kohm and add a Zehner that makes sure that the votlage on the pin does not get above 6V. I would add some margin there as the input voltage will have some fluctuation and spikes, so 12V is already too high, I think.

    Best regards,
    Brigitte