In case of short-circuiting the output to GND or under excessive load conditions, the regulator is forced to deliver a very high output current. To protect the application as well as the regulator itself against damage, the IC limits the output current. Values are specified in the datasheet.
Two types of protection could be implemented: constant or fold-back current limitation. Infineon linear regulators use constant current limitation in order to overcome “latch-up” problems with the fold-back limiting method: If the load draws a current anywhere along the fold-back curve after the removal of the fault condition, the output will never reestablish its original voltage.
During start-up, the output capacitor is charged up with the maximum output current. Hence, the time until nominal output voltage is reached after turning on the IC or applying an input voltage is calculated as t STARTUP = V Q x C Q/I Q,MAX.