PG Misbehaving When EXTVCC is powered before VIN

Hi All,

I have noticed that the power good (PG) pin is misbehaving when powering up the IC from EXTVCC. 

The sequence is as follows:

1. VIN is off
2. EXTVCC turned on (not derived from VOUT)
3. RUN is low
4. PG measured to be high. 

If you then turn on VIN, PG goes low during the soft-start and then high after the output voltage is within 10% of VOUT. This is as expected.

If you now turn-off everything and repeat the sequence above right afterwards, the PG stays low. When measuring the resistance PG to GND while everything is off (after the IC ones hat VIN supply) the PG FET seems to be still on (50Ohm to GND). Only after multiple hours the internal FET seems to turn-off. 

Could you please confirm whether the internal FET has an active pull-down on the gate? If not, the behaviour would make sense and we would stop investigating it.