SLVA528D September 2012 – August 2021 TPS65381-Q1 , TPS65381A-Q1
The SEL_VDD3/5 pin selects the output voltage level (not connected or open selects 3.3 V, pin to ground selects 5 V). The state of this pin is sampled and latched at power up from the STANDBY state. After latching at power up, any later change in the state of this pin does not change the output voltage level of the VDD3/5 regulator.
A current limit protects this output against shorts to ground and limits output voltage overshoot during power up or during line or load transients. Current limit and overtemperature protection circuits protect the internal MOSFET against excess power dissipation.