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.
After overcurrent is detected the output switches to a current limited state and the restricted current is output. The output voltage at that time is calculated by 'Overcurrent Limit Value (Short-Circuit Output Current) x Load Resistance Component'. If this condition continues the chip temperature will increase and the thermal shutdown circuit will operate to switch OFF the output. Thermal shutdown is cancelled when the temperature decreases. For the following latch-type models, after overcurrent detection the outgoes to a current-limited state and limited current is output. If this condition continues and the time specified by the /OC output delay time comes, the latch turns OFF and no current is output.
The /OC pin (flag) goes to 'L' upon detection of overcurrent or overtemperature. The reason for switching between 'L' and 'H' after overcurrent detection is because the /OC pin is linked to the thermal shutdown circuit. Depending on the model, however, the /OC pin may not be linked to repeated 'H' and 'L' thermal shutdown operation.