The device operates when EN is set high. The device enters a shutdown sequence when EN is set to GND. During the shutdown sequence, the regulator stops switching, all internal control circuitry is switched off, and the load is disconnected from the input. It is possible for the output voltage to drop below the input voltage during shutdown. During the start-up sequence, the device limits the duty cycle and the peak current in order to avoid high peak currents flowing from the input.