FET pinch off and cutoff voltage

snipped-for-privacy@hanmail.net wrote in news: snipped-for-privacy@j33g2000cwa.googlegroups.com:

As I remember it, the FET has a channel between soucre and drain, and the gate region increases with applied voltage until the region is as wide as the channel, preventing current flow through it.

I'm sure that can easily be expressed better than I did it there, but I think it implies that whether you call it 'pinch' or 'cut', the method is the same. If there is a difference, it's probably that pinch-off is the exact point at which current reduces to being immeasurable, and cut-off might at a larger gate voltage to be sure of cutting off. If so, cutoff would be useful in switching operations, but pinch-off would be useful in proportional ones.