The specified input voltage value of the EN (CTRL) pin will not be the same since it is dependent on the supply voltage. When using with IN=3.3V refer to the following graphs in the datasheet. BD6520F and BD6522: Control Input Voltage vs Supply Voltage, BD6524HFV: EN Input Voltage vs Ambient Temperature, and for other models: EN, /EN Input Voltage vs Supply Voltage.
. With backflow models, if a higher voltage is supplied to OUT vs IN when the switch is OFF (EN=OFF), current may flow (i.e. through a parasitic diode), which can lead to deterioration and breakdown. If applying a higher voltage to OUT than IN, please use a model that can prevent backflow. Applicable models are described as providing 'reverse current protection while the switch is OFF' in the datasheet.Related Link：Technical Document
There should be no problems even if a large capacitance capacitor (USB standard, 120uF or more) is connected to the output. However, when the IC turns ON and the output rises the capacitor CL is charged, causing inrush current to flow. Depending on the value of CL, the inrush current is restricted to the current limit value and the IC enters an overcurrent detection state. If the high-side switch IC continues in this state for more than the /OC pin (flag) output delay time, 'L' is output from the /OC pin.
UVLO is a function that forcibly turns OFF when the IN pin voltage drops below the UVLO threshold. The threshold has upper and lower hysteresis, and both upper and lower sides are set below the operating supply voltage.