• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 243 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.

Original question:

TPS22810: Using Voltage divider for EN/UVLO

TPS22810: Can EN pin be connected to VIN, i.e. switch always ON?

Noman Paracha
Intellectual 570 points
Part Number: TPS22810

Hi Team,

Can I tie EN pin to VIN pin such that the switch is always in ON position? Datasheet says Ven can be up to 18V and in my case Vin is 12V. If I do this, what will be the inrush current? The whole reason for using this part is to limit inrush current into my regulators.

Thanks,

Noman

  • 0
    TI__Mastermind 32650 points

    Hi Noman,

    Firstly, yes the enable pin can be driven up to voltages of 18V. EN being tied to VIN which is 12V is an acceptable use case for this device. 

    Secondly, the EN pin has no bearing on the inrush current. Inrush current is limited by the input voltage, the output capacitance and the CT capacitance you use. Driving the EN pin with a 12V source will not change the inrush current when compared to driving it with a source that only rises up to 5V. The EN pin is solely a control pin.

    In your situation when tying EN to VIN, timing will be the major consideration. The reason is that if the VIN ramp rate is very slow, your inrush current will be limited by your supply ramp rate and not the device. If the 12V ramp is quick, tying to the EN pin will turn on the device and the output will soft start as expected.