material with two terminals called the "source" and the
"drain", and an adjoining region of
acceptor material
between, called the "gate". The voltage between the gate and
the
substrate controls the current flow between source and
drain by depleting the donor region of its charge carriers to
greater or lesser extent.
Because no current (except a minute leakage current) flows
through the gate, FETs can be used to make circuits with very
low power consumption.
(1995-10-05)