aaron_do
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Hi all,
thanks for the replies.
I guess what I'm trying to say is that in my case, there's a tipping point. The current shouldn't change much as its just a small change in the biasing (and it actually shouldn't directly affect current anyway). Also, after the breakdown, the circuit no longer functions and there is a small leakage current from the supply.
From analyzing the circuit, its possibly a high VDS (punch through), a high VGD (gate dielectric), or even high current at high VDS (HCI). But my thinking is that if there isn't an enormous current, then the circuit should be able to recover from punch through. Also, HCI is more of a long-term degradation mechanism. That leaves gate dielectric breakdown. From personal experience, I feel that this is most likely the cause as the circuit will seem OK until the break point is reached, at which point it will just die...
So just curious if any other explanations are possible. Also, sorry that I can't provide schematics as its a little sensitive.
regards, Aaron
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