I am wondering about catch diodes in the context of switching power supplies. I have read all the books that are the norm in designing a SMPS, but all of them don't or barely touch the subject. My question is about how do you select it's current and voltage rating.
From a buck converter standpoint I have reached the (maybe bad) conclusion, that the current rating of the diode must be equal or larger than the current flowing through the load, since the inductor stores energy then it returns it to the load through the diode. But in an SMPS with a transformer, which ideally only transfers energy, the diode selection would be based on the leakage inductance. If so, how do you select the ratings?