Characteristic of F-shaped pattern

One of the methods for short-circuit current reduction circuits (short-circuit protection) in switching power supplies. It is named "F-letter characteristic" because the protection characteristic curve of output voltage and output current when the protection function operates resembles the shape of the letter "F". It is also called F-letter drooping characteristic. In contrast to the inverse-L droop characteristic typically used in short-circuit current reduction circuits, which tries to maintain a constant current even when output voltage drops due to protection, the F-letter characteristic reduces the overcurrent set value as the output voltage drops. Switching power supplies with an F-letter characteristic may not be usable with some loads that fail to start, so it is necessary to confirm compatibility before use.