Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Mosfets Biasing Enhanced-Type Mosfets?

  1. Jun 15, 2012 #1
    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)
     
  2. jcsd
  3. Jun 15, 2012 #2
    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.
     
  4. Jun 15, 2012 #3
    Thanks yungman, that's what I foresaw.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Mosfets Biasing Enhanced-Type Mosfets?
  1. Mosfet drive (Replies: 4)

  2. MOSFET properties (Replies: 2)

Loading...