How badly is Schottky diode damaged by overvoltages?

[cupoftea]

Hi,
We wish to use the 60V Schottky STPS20M60SG-TR (D2PAK) in a Buck with 24vin, 13v5 out 15A out and 450kHz. (as attached LTspice and .PNG)

Schottky STPS20M60SG-TR

https://www.st.com/content/ccc/resource/technical/document/datasheet/d6/86/ed/66/74/b5/4d/c4/DM00034248.pdf/files/DM00034248.pdf/jcr:content/translations/en.DM00034248.pdf

Supposing the spikes on it, due to poor circuit stray L , was as attached, (67v pk). Would this result in a shortened
lifetime of this Schottky?

 

[danadakk]

Thats a sim you show. First I would ask what timestep are you using, something on
order of 10 nSec should be used.

Two sim does not have stray L in it due to layout, PCB, possible transient even higher.

Three verify situation with PCB layout and actual probing.

Four even though "most" test programs have margin in them thats typical margin
at room test put into test program. Forum frequently gets asked by users is can they
violate datasheet specs. Sure, go ahead, that will result in early retirement for you
when management figures out you designed with no margin.

Landfills are full of margin-less designs, sad commentary on engineering.


Regards, Dana.

 

[Easy peasy]

Schottkies are extremely - and fatally - susceptible to over-voltages as brief as 20nS, for more than a few volts over rated

this is why you often see them fairly well snubbed in ckts that are expected to run for years.

 

[dick_freebird]

See a lot of the high voltage SiC Schottkies failing at
below rated voltage under heavy-ion irradiation. The
advantages of extremely high field operation "go away"
when field-uniformity as-designed is compromised.

Oddly the fail site photos I've seen are always at the
guardring.