SLVU411A September 2010 – June 2021 TPS62120
J8 pin 1 is connected to the Power Good (PG) output of the TPS62120. This open drain output is pulled up to VOUT with R3. PG output goes high when the FB voltage rises above 95% (typ) of its nominal value. PG goes low when the FB voltage drops below 90% (typ) of its nominal value.