When Enable (EN) is set High, the device starts operation. Shutdown is forced if EN is pulled Low with a shutdown current of typically 1.5 µA. During shutdown, the internal power MOSFETs as well as the entire control circuitry are turned off. The EN signal must be set externally to High or Low. An internal pull-down resistor of about 400 kΩ is connected and keeps EN logic low, if the pin is floating. It is disconnected if the pin is High.
Connecting the EN pin to an appropriate output signal of another power rail provides sequencing of multiple power rails.