Could somebody tell me what is the function of Q30 Mosfet in DC Jack sub-circuit?

Hi,

I am designing a Jetson tx1 carrier board for a car vision systems. I understand there is a power on and off sequencing circuit for the safe operation. I refer the hardware from Jetson_tx1 Developer_Kit Carrier Board Design Files_B04. In Page 27 of DC Jack sub circuit, there is a mosfet Q30, I cannot figure out its function and why and how it works?

Could any give me a clue? Any help will be most appreciated.

Feiw

Q30 is to avoid peak high voltage level and inrush current damage when plug in. When DC plug in, Q30 shut off at first and turn on after C501 is full charged and input voltage is stable.

Hi Trumany,

Thank you very much for your answer.
Best,
Feiw