Re: FETs and MOSFETs

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Mddeming-at-aol-dot-com>

In a message dated 6/15/02 7:49:16 PM Eastern Daylight Time, tesla-at-pupman-dot-com
writes:



>
> > hi all
> >
> > can anyone help me (again!! :-)): what exactly are FETs and MOSFETs and
> what
> > are they used for? also, what are MMCs?
> >



FET = Field-Effect Transistors - Devices in which an electric field is used to
control the conductance of a semiconductor crystal.First proposed by Julius
Lilienfeld ca. 1927.

JFET = Junction Field-Effect Transistor - Developed in the late 1940's,
characterized by extremely high input impedance.

MOSFET = Metal Oxide Semiconductor Field-Effect Transistor - First proposed by
Kahng in 1960, theory of operation published by Hofstein & Heiman in 1963.
MOSFETs are structurally simpler, require fewer processing steps, and can be
made considerably smaller than comparable bipolar junction transistors. The
transfer characteristic of a MOSFET is essentially that desired of a logic NOT
gate and as such, any logic circuit can be constructed entirely of MOSFETs.
CMOS (Complementary metal oxide Semiconductor) logic circuits are widely used,
since no space on the chip is required for resistor elements. Dynamic memory is
essentially a whole sheet of microscopic MOSFET-type devices. 
Individual MOSFETs are used as amplifiers, inverter circuits, logic gates, and
high-speed switching devices, some of which can handle considerable power.
For more detail than you may ever need, see "Electronic Concepts" by Jerrold
Krenz,(Cambridge Univ. Press 2000) ISBN 0-521-66282-6 Contains much theory and
many SPICE program runs involving MOSFETs.

Matt D.