TPS62813-Q1: PG connects to the external power

Dear team,

We use 62813's PG signal as a trigger signal which will connect to TCA9539-Q1. The VIH voltage of TCA9539-Q1 is 2.3V, but 62813's output is only 0.8V, so we need to connect PG pin to an external 3.3V instead of the output voltage 0.8V.  PG is an open-drain output, so in my understanding it is ok that PG connects to an external 3.3V. Because the pull up voltage has no relationship with TPS62813-Q1's power rails(input/output), right?

Thanks & Regards,

Sherry