The LP5912-EP has a power-good function that works by toggling the state of the PG output pin. When the output voltage falls below the PG threshold voltage (PG_LTH), the PG pin open-drain output engages (low impedance to GND). When the output voltage rises above the PG threshold voltage (PGV_HTH), the PG pin becomes high impedance. By connecting a pullup resistor to an external supply, any downstream device can receive PG as a logic signal. Make sure that the external pullup supply voltage results in a valid logic signal for the receiving device or devices. Use a pullup resistor from 10 kΩ to 100 kΩ for best results.

The input supply, V_IN, must be no less than the minimum operating voltage of 1.6 V to ensure that the PG pin output status is valid. The PG pin output status is undefined when V_IN is less than 1.6 V.

In the power-good function, the PG output pin being pulled high is typically delayed 140 µs after the output voltage rises above the PG_HTH threshold voltage. If the output voltage rises above the PG_HTH threshold and then falls below the PG_LTH threshold voltage, the PG pin falls immediately with no delay time.

If the PG function is not needed, the pullup resistor can be eliminated, and the PG pin can be either connected to ground or left floating.