| .:Insulated Gate Bipolar Transistors
(IGBT)
Insulated gate bipolar transistors (IGBTs) are semiconductors
that combine the simple gate-drive characteristics of the
MOSFETs with the high-current and low–saturation-voltage
capability of bipolar transistors by combining an isolated
gate FET for the control input, and a bipolar power transistor
as a switch, in a single device. Consequently, IGBTs provide
faster speeds and better drive and output characteristics
than power BJTs and offer higher current densities than equivalent
high-powered MOSFETs.
Performance specifications for insulated gate bipolar transistors
(IGBTs) include collector-emitter breakdown voltage, collector-emitter
“on” or saturation voltage, maximum collector
current, gate-emitter leakage current, rise time, fall time,
switching speed, power dissipation and temperature.
The IGBT is used in medium- to high-power applications such
as switched-mode power supply, traction motor control and
induction heating.
Packing methods for insulated gate bipolar transistors (IGBTs)
consist of bulk pack, tape reel, rail, and tube technologies.
.
.: Darlington Transistors
Darlington transistor is an eletrical device consisting of
two integrated or seperated bipolar transistors connected
in such a way that the current amplified by the first transistor
is amplified further by the second one. In Darlington pairs,
transistor collectors are tied together and the emitter of
the first transistor is directly coupled to the base of the
second transistor. The total gain, which is often 1000 or
more, is the product of the gain of the individual transistors.
Compared to single transistor configurations, Darlington transistor
pairs have more phase shift at high frequencies and can become
unstable with negative feedback more easily.
Darlington transistors are used for applications including
audio outputs, power supply outputs, display drivers and the
like.
.:MOSFET
MOSFET, or metal–oxide–semiconductor field-effect transistor,
is a device used for amplifying or switching electronic signals.
It is by far the most popular transistor in both digital and
analog circuits. MOSFETs are either NMOS (n-channel) or PMOS
(p-channel) transistors, which are fabricated as individually
packaged discrete components for high power applications as
well as by the hundreds of millions inside a single chip (IC).
The Power MOSFETs that are available today have the same
function as Bipolar transistors
except they are voltage controlled compared with the current
controlled Bipolar devices.
MOSFETs are popular because of high impedance without thermal
loss, second breakdown and minority carrier storage time effects.
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