[Amps] LDMOSFET questions for insiders

[Manfred Mornhinweg]

Doug,

thanks for that link. What I take home from reading it is that I should
expect a somewhat reduced total dissipation capability when avalanching 
is involved.

But doubts remain as to whether that fully applies to LDMOSFETs used in 
RF amplifiers, and of course the actual avalanche energy and power 
ratings of the specific LDMOSFETs I might use.

The paper is specific to VDMOSFETs operating in switched mode with 
inductive loads. An LDMOSFET might behave differently (I don't know), 
and in RF amplifier use there can be avalanching while the device is 
still partially on. I would imagine that this is a particularly critical 
operating condition, leading to lower avalanching specs than for 
inductive switching, but I can't find any data on it.

Could it really be that nobody has ever investigated this and published 
on it?

Manfred


> This app note gives some information on repetitive avalanche 
> ruggedness and unclamped inductive switching which may help... 
> https://assets.nexperia.com/documents/application-note/AN10273.pdf


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