A transistor is a semiconductor device that is used
as an amplifier, as the circuit breaker and junction (switching), voltage
stabilization, signal modulation or as other functions. Such transistors can
function electric faucet, which is based on input current (BJT) or input
voltage (FET), enabling highly accurate power drainage from the electrical
source circuit.
Transistor through-hole (compared with centimeter measuring tape)
Transistor through-hole (compared with centimeter measuring tape)
In general, the transistor has three terminals, namely Base (B), emitter (E) and collector (C). The voltage at the emitter terminal for instance can be used to regulate current and voltage greater than the input current Base, which is the output voltage and output current collector.
Transistor is a very important component in modern electronic world. In analog circuits, transistors are used in amplifiers (amplifier). Analog circuits surround loudspeakers, a stable power source (stabilizers) and the radio signal amplifier. In digital circuits, transistors are used as high-speed switches. Some transistors can also be arranged in such a way that it serves as a logic gate, memory and function other circuits.
Basically, transistors and vacuum tubes have a similar function, both of which
regulate the amount of electrical current flow.
To understand the workings of semiconductors, for example a glass of pure water. If a pair of conductors inserted into it, and given the right under the DC voltage electrolysis voltage (before the water turns into Hydrogen and Oxygen), there will be no current flow because the water does not have a charge carrier (charge carriers). Thus, pure water is considered as an insulator. If a little salt put into it, the conduction current will begin to flow, as a number of free charge carriers (mobile carriers, ion) is formed. Increase the salt concentration will increase conduction, but not much. Salt itself is a non-conductor (insulator), because the carrier charge not free.
Pure silicon itself is an insulator, but if a pollutant is added, such as Arsenic, by a process called doping, in quantities small enough so it does not mess up the layout of crystalline silicon, arsenic will provide free electrons and the results allow the conduction of electrical current. Arsenic has a 5 is because the atoms in the outermost orbit, while the silicon is only 4. Conduction occurs because the free charge carrier was added (by excess electrons of Arsenic). In this case, an n-type silicon (n for negative, because the charge carriers are electrons which are negatively charged) has been formed.
In addition, silicon can be mixed with boron to make a p-type semiconductor. Because Boron only has 3 electrons in the outer orbit, a new cargo carrier, called "holes" (holes, positive charge carriers), will be formed in the silicon crystal layout.
To understand the workings of semiconductors, for example a glass of pure water. If a pair of conductors inserted into it, and given the right under the DC voltage electrolysis voltage (before the water turns into Hydrogen and Oxygen), there will be no current flow because the water does not have a charge carrier (charge carriers). Thus, pure water is considered as an insulator. If a little salt put into it, the conduction current will begin to flow, as a number of free charge carriers (mobile carriers, ion) is formed. Increase the salt concentration will increase conduction, but not much. Salt itself is a non-conductor (insulator), because the carrier charge not free.
Pure silicon itself is an insulator, but if a pollutant is added, such as Arsenic, by a process called doping, in quantities small enough so it does not mess up the layout of crystalline silicon, arsenic will provide free electrons and the results allow the conduction of electrical current. Arsenic has a 5 is because the atoms in the outermost orbit, while the silicon is only 4. Conduction occurs because the free charge carrier was added (by excess electrons of Arsenic). In this case, an n-type silicon (n for negative, because the charge carriers are electrons which are negatively charged) has been formed.
In addition, silicon can be mixed with boron to make a p-type semiconductor. Because Boron only has 3 electrons in the outer orbit, a new cargo carrier, called "holes" (holes, positive charge carriers), will be formed in the silicon crystal layout.
In a vacuum tube, the charge carriers (electrons) will be emitted by thermionic
emission from the cathode is heated by a wire filament. Therefore, the vacuum
tube could not make a positive charge carriers (holes).
It can be seen that the charge carriers are equal charges repel each other, so that in the absence of other forces, the charge carriers will be distributed evenly within the semiconductor material. But in a bipolar transistor (or diode junction) where a p-type semiconductor and an n-type semiconductor made in a single piece of silicon, the charge carriers tend to move in the direction of the PN junction (boundary between p-type semiconductor and type -n), because they are attracted by opposite charges of the opposite.
The increase of the amount of pollutants (doping level) will increase the conductivity of the semiconductor material, provided that the layout of the silicon crystal is maintained. In a bipolar transistor, the emitter terminal region has a doping amount greater than the base terminal. Doping ratio between the emitter and the base is one of the many factors that determine the nature of the current gain (current gain) of the transistor.
It can be seen that the charge carriers are equal charges repel each other, so that in the absence of other forces, the charge carriers will be distributed evenly within the semiconductor material. But in a bipolar transistor (or diode junction) where a p-type semiconductor and an n-type semiconductor made in a single piece of silicon, the charge carriers tend to move in the direction of the PN junction (boundary between p-type semiconductor and type -n), because they are attracted by opposite charges of the opposite.
The increase of the amount of pollutants (doping level) will increase the conductivity of the semiconductor material, provided that the layout of the silicon crystal is maintained. In a bipolar transistor, the emitter terminal region has a doping amount greater than the base terminal. Doping ratio between the emitter and the base is one of the many factors that determine the nature of the current gain (current gain) of the transistor.
Required number of doping a semiconductor is very small, the size of the one in
a hundred million, and is the key to the success of the semiconductor. In a
metal, the charge carrier population is extremely high, the charge carrier for
each atom. In metal, metal to turn into an insulator, the charge carriers must
be swept away by installing a different voltage. In the metal, the voltage is
very high, much higher than that can destroy it. However, in a semiconductor
there is only one charge carrier in a few million atoms. The amount of voltage
required to sweep a large number of charge carriers in a semiconductor can be
reached easily. In other words, the electricity in the metal is not compressed, like fluid. Whereas in semiconductors, electrical nature such
as compressed gas can. Semiconductors by doping can be converted into an insulator,
while metal is not.
The above description describes the conductivity caused by charge carriers, ie electrons or holes, but is essentially bipolar transistor action activities of the charge carriers to cross the depletion zone area. Depletion zone is formed by the transistors given reverse bias voltage, by a voltage applied between the base and emitter. Although it looks like a transistor formed by two diode connected, a transistor itself can not be made by connecting two diodes. To make transistors, the parts must be made from a piece of crystalline silicon, with a very thin base region.
Of the many types of modern transistors, initially there are two basic types of transistors, bipolar junction transistor (BJT or bipolar transistor) and field-effect transistor (FET), which each works differently.
The above description describes the conductivity caused by charge carriers, ie electrons or holes, but is essentially bipolar transistor action activities of the charge carriers to cross the depletion zone area. Depletion zone is formed by the transistors given reverse bias voltage, by a voltage applied between the base and emitter. Although it looks like a transistor formed by two diode connected, a transistor itself can not be made by connecting two diodes. To make transistors, the parts must be made from a piece of crystalline silicon, with a very thin base region.
Of the many types of modern transistors, initially there are two basic types of transistors, bipolar junction transistor (BJT or bipolar transistor) and field-effect transistor (FET), which each works differently.
Bipolar transistors are so named because the main conduction channel using two
polarity charge carriers: electrons and holes, to carry electric current. In
BJT, the main electric current must pass through a region / boundary layer
called the depletion zone, and the thickness of this layer can be set at high
speed in order to regulate the flow of the main stream.
FET (also called unipolar transistors) using only one type of charge carriers (electrons or holes, depending on the type FET). In the FET, the main electric current flowing in a narrow conduction channel with a depletion zone on either side (compared to the bipolar transistor in which the base area of the main cutting direction of the electric current). And the thickness of the border area can be changed with the change of applied voltage, to change the thickness of the conduction channel. See the article for each type for further explanation.
FET (also called unipolar transistors) using only one type of charge carriers (electrons or holes, depending on the type FET). In the FET, the main electric current flowing in a narrow conduction channel with a depletion zone on either side (compared to the bipolar transistor in which the base area of the main cutting direction of the electric current). And the thickness of the border area can be changed with the change of applied voltage, to change the thickness of the conduction channel. See the article for each type for further explanation.
In general, the transistor can be differentiated based on many categories:
- Semiconductor materials: Germanium, Silicon, gallium arsenide
- Physical Packaging: Through Hole Metal, Plastic Through Hole, Surface Mount, IC, etc.
- Type: UJT, BJT, JFET, IGFET (MOSFET), IGBT, HBT, MISFET, VMOSFET, MESFET, HEMT, SCR and the development of the transistor is IC (Integrated Circuit) and others.
- Polarity: NPN or N-channel, PNP or P-channel
- Maximum capacity: Low Power, Medium Power, High Power
- Maximum operating frequency: Low, Medium, or High Frequency, RF transistors, Microwave, etc.
- Application: Amplifiers, Switches, General Purpose, Audio, High Voltage, and others