The Power Good assertion threshold can be set using the resistors R3 and R4 connected to the PGTH pin whose values can be calculated as:

Because R3 and R4 leak the current from the output rail V_OUT, these resistors must be selected to minimize the leakage current. The current drawn by R3 and R4 from the power supply is IR34 = V_OUT / (R3 + R4). However, leakage currents due to external active components connected to the resistor string can add error to these calculations. So, the resistor string current, IR34, must be chosen to be 20 times greater than the PGTH leakage current expected. From the device electrical specifications, PGTH leakage current is 1 μA (maximum), V_PGTH(R) = 1.2 V and from design requirements, V_PG = 4.5 V. To solve the equation, first choose the value of R3 = 100 kΩ and calculate R4 = 36.4 kΩ. Choose nearest 1% standard resistor value as R4 = 36.5 kΩ.