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Changing Diode DC Blocking Voltage
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b2theory:
Has anyone seen the blocking voltage on diodes change (reliably) in the field?
bob91343:
no
Gyro:
I suppose avalanching a non avalanche rated diode could change it's reverse breakdown voltage, but not predictably (unless it goes to zero!).

You need to provide some explanation of the reason for your question if you expect a sensible answer.
b2theory:
I suppose avalanching a non avalanche rated diode could change it's reverse breakdown voltage, but not predictably (unless it goes to zero!).

You need to provide some explanation of the reason for your question if you expect a sensible answer.

It's a 200V schottky diode used in a buck regulator. Without getting too deep into the weeds about the end use, the diode is substantially over spec'd for the circuit. We are noticing anomalies in the regulator output on a few return units. During our investigation we put the diode on a curve tracer and found that it was breaking over at 300V. We also know if you touch the "malfunctioning" diode in circuit the regulator output changes.

I have seen papers showing the over drive of certain power MOSFETs gates can cause the Vth to drift without resulting in a catastrophic device failure. I was wondering if anyone was aware of an equivalent phenomenon in diodes.   
amyk:
A diode rated for 200V is unlikely to go into reverse breakdown at exactly 200V, unless it is a zener. In fact it is normal for the actual value to be higher to accommodate natural statistical process variation. The results here show that the common 1n400x series may all be the same internally (and the actual breakdown voltage is much higher than the spec):

https://www.eevblog.com/forum/projects/testing-1n4007-with-a-megger/
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