Mosfets Biasing Enhanced-Type Mosfets?

[M. next]

Simple Question: Do Enhanced-Type Mosfets (And not Depletion Type ones) have Fixed Bias Configuration? If yes how do we draw the transfer curve? And locate Q point?
(I didnt seem to find it in the book, only present for Depletion types)

 

[yungman]

It is not advisable to use a fixed voltage to bias an Enhancement MOSFET. The turn on voltage is very unpredictable, it can vary a lot between parts. Also temp. drift is very large. You have to use source resistor degeneration to stabilize the current.

Case in point, propagation delay in CMOS logics change quite a bit with temperature. This is because the switching threshold drift with temperature and the propagation delay change because of the rise time of the driving output. I had to design the critical timing circuits with bipolar logics.

 

[M. next]

Thanks yungman, that's what I foresaw.