Hello everybody. I'm going to try working a bit with mosfets. Can anybody give some suggestions on how to bias them? Do they bias like tubes? Or are they a different topology all their own???
They bias somewhat like pentodes but with the grid voltages shifted up -- For an N channel device generally you have to make Vgs (gate to source voltage) positive to get any drain current, rather than having current at zero grid voltage and having to go negative to turn it lower.
Some books to consider getting:
The Art of Electronics, Horowitz and Hill
Microelectronic Circuits, Sedra and Smith : http://www.sedrasmith.org/
look up things like "mosfet I-V curves" on google. more and more universties are putting great stuff out on the web.
For example, this is an excel spreadsheet that plots curves given device parameters. You can (sometimes) extract appropriate device parameters from spice model files or from data sheets once you know what they mean.
http://ece-www.colorado.edu/~bart/book/mosfetiv.xls
You can also find great course notes from Stanford, Berkeley, MIT -- you just have to search. Especially search for things like analog design courses, analog IC design, ...
Have fun. Google is your friend.
Some books to consider getting:
The Art of Electronics, Horowitz and Hill
Microelectronic Circuits, Sedra and Smith : http://www.sedrasmith.org/
look up things like "mosfet I-V curves" on google. more and more universties are putting great stuff out on the web.
For example, this is an excel spreadsheet that plots curves given device parameters. You can (sometimes) extract appropriate device parameters from spice model files or from data sheets once you know what they mean.
http://ece-www.colorado.edu/~bart/book/mosfetiv.xls
You can also find great course notes from Stanford, Berkeley, MIT -- you just have to search. Especially search for things like analog design courses, analog IC design, ...
Have fun. Google is your friend.
Also try http://www.irf.com ---
International Rectifier has a lot of application notes that might come in handy.
International Rectifier has a lot of application notes that might come in handy.
If you check out the A75 and the several Zen amp articles at
www.passdiy.com , I tried to put Mosfet tutorial sections
in each of them, and you might find those helpful.
www.passdiy.com , I tried to put Mosfet tutorial sections
in each of them, and you might find those helpful.
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