in
,
added a third element, called the
vacuum diode, resulting in the
In
, the
, the
, to the
.
was , Dr. S. William
, Walter H.
the
, and John
of the
at the Bell
Telephone Laboratories is a
device consisting of either layers of material or
layers of material
The
is
decreases the
this material
, with the
the term
the number of
If only
The
(increases the resistance) of .
reflects the fact that into the
only
participate in the material.
is employed (electron or hole), it is considered a
, however, comprises
—the
and
the
The
component is called the
symbol
The
in the graphic symbol
(conventional (conventional flow) through the device.
and is given the
The output or collector set of characteristics has three basic regions of interest: the
,
, and
In the
the
In the
the
. , whereas the
and
transistor are
junctions of a
.
In the
the
In the dc mode the levels of
junctions are
due to the majority carriers are related
by a quantity called
The
is formally called the
Two sets of characteristics are again necessary to describe fully : one for the and one for the
In the
. of a common-emitter common-emitter amplifier, the
, whereas the
junction is
junction is .
For linear (least distortion) amplification purposes, cutoff for the commonemitter configuration will be defined by I C = ICEO.
In the dc mode the levels of
the formal name for
is
are related by a quantity called
an increase in current is resulting in a
drop in voltage
The
is used primarily for impedance-matching
purposes since it has a high input impedance and low output impedance, opposite to that of the common-base and common emitter configurations. in
that the
of an
will primarily to
as a
process
toward
and
is developing a
that employs to
that
as
Semiconductor Semiconductor devices have the following advantages over vacuum tubes: They are more
of
size ,
The
more
,
. In addition, they have
requirement , and
transistors
operating is always the l
is always the
. The
more
, and
period , . current of a transistor, whereas the is always the
