buck converter freewheeling diode current

[Magdy_said]

i am a new to power electronics field and trying to design a simple buck converter, i started with simulation before real acting but i noticed something wired in diode current, it reaches 28 amps in first 200us is that usaul? is this just a transint wave that won't affect the circuit? will 4 amp diode can handle this 28 amp transients?!

 

[KlausST]

Hi,

Without a look into the datasheet .. I assume this is the so called "reverse recovery current" or current caused by stray capacitance.

The magnitude depends on the diode but also on the rise/fall rate of the signal. I assume in reality the current is much lower.

Klaus

 

[Akanimo]

Hi,
Klaus has said it that the current in the real converter would be less than the value you obtained in simulation. Moreover the average of the current shown in simulation is far less than 4A and the non−repetitive peak surge current for the diode should be far higher than 28A.

Your diode will be cool.