Power good is an open-drain output that requires a pullup resistor to any voltage up to the recommended input voltage level. It is driven by a window comparator. PG is held low when the device is disabled, in undervoltage lockout in thermal shutdown, and not in soft start. When the output voltage is in regulation hence, within the window defined in the electrical characteristics, the output is high impedance.
VIN must remain present for the PG pin to stay low. If the power good output is not used, it is recommended to tie it to GND or leave open. The PG indicator features a de-glitch, as specified in the electrical characteristics, for the transition from "high impedance" to "low" of its output.
|EN||DEVICE STATUS||PG STATE|
|X||VIN < 2 V||undefined|
|low||VIN ≥ 2 V||low|
|high||2 V ≤ VIN ≤ UVLO OR in thermal shutdown OR VOUT not in regulation OR device in soft start||low|
|high||VOUT in regulation||high impedance|