I'm wondering if a pull-up resistor is not connected between reg and fault pin on ADP8140.
Do I have to connect the resistor even the fault signal is not used in my design?
FAULT pin is an open drain output so if not used or not connected to any part of circuit, you may leave pin open (no pull-up resistor connected).
I'd like to share something about the fault pin info with you.
according to Jon, it might be necessary to put resistor between nFault and Vreg.
As a fact, my circuit worked after adding the resistor.
Thank you for this info!