I think Sarma is right. The IRFxxx MOSFETS are
really on/off switches. They have a small linear region which
can be used for RF, but they are really designed to be "all on" or "all off".
That means that once they start conducting, they are very fast.
Whatever happens takes microseconds to accomplish. What
device is fast enough to stop that? That is the real question.
And even several amperes over a micro-sized circuit for even a few
microseconds represents a lot of joules of energy...which is why it
is relatively easy to blow up a IRF510. It goes along with the design...
john
AD5YE
