The device operates in standby mode when the supply voltage is greater than the UVLO threshold (and the device has completed its initialization) and any of the following conditions is true:

• A low level is applied to the EN pin.
• SWEN = 0 in the CONTROL1 register.
• The device junction temperature is greater than the thermal shutdown threshold.
• The supply voltage is greater than the OVLO threshold.

The device initializes for 400 µs (typical) after the supply voltage increases above the UVLO threshold voltage following a device power-on reset. If the supply voltage decreases below the UVLO threshold but not below the POR threshold, the device does not reinitialize when the supply voltage increases again. During initialization, the device reads the state of the FSEL, VSEL, and SYNC_OUT pins.

The following functions are available in standby mode:

• I²C interface
• Output discharge
• Power good

The device leaves standby mode and enters UVLO mode when the supply voltage decreases below the UVLO threshold. The device leaves standby mode and enters on mode when all of the following conditions are true:

• A high-level is applied to the EN pin.
• SWEN = 1 in the CONTROL1 register.
• The device junction temperature is below the thermal shutdown threshold.
• The supply voltage is below the OVLO threshold.