Bipolar junction transistor, Electrical Engineering

Assignment Help:

Bipolar junction transistor:

Transistors are so named as they conduct via using both majority and minority carriers. The bipolar junction transistor that is abbreviated as BJT, the first type of transistor to be mass-produced, is a mixture of two junction diodes, and is made up of either a thin layer of p-type semiconductor sandwiched among the two n-type semiconductors (an n-p-n transistor), or a thin layer of n-type semiconductor sandwiched among the two p-type semiconductors (a p-n-p transistor). This construction generates two p-n junctions: a base-emitter junction and a base-collector junction, separated via a thin region of semiconductor termed as the base region (two junction diodes wired together with no sharing an intervening semiconducting region will not make a transistor).

The BJT or bipolar junction transistor has three terminals that are corresponding to the three layers of semiconductor - an emitter, base, and collector. It is helpful in amplifiers as the currents at the emitter and collector are controllable through a comparatively small base current." In the active region, the emitter-base junction is forward biased and electrons are injected into the base region, in an NPN transistor operating. Since the base is narrow, most of these electrons will diffuse into the reverse-biased (electrons and holes are made at, and move away from the junction) base-collector junction and be swept into the collector; may be one-hundredth of the electrons will recombine in the base that is the dominant mechanism in the base current. Through controlling the number of electrons which can leave the base, the number (digit) of electrons entering the collector can be controlled. Collector current is almost β (common-emitter current gain) times the base current. It is commonly greater than 100 for small-signal transistors but can be much smaller in transistors intended for high-power applications.


Related Discussions:- Bipolar junction transistor

What is expanded memory system, What is expanded memory system? EMS: Th...

What is expanded memory system? EMS: The area at location C8000H-DFFFFFH is frequently open or free. Such area is used for the expanded memory system into a XT or PC system, or

Evaluate supply and the supply power factor, Q. Two balanced, three-phase, ...

Q. Two balanced, three-phase, wye-connected loads are in parallel across a balanced three-phase supply. Load 1 draws a current of 20 A at 0.8 power factor leading, and load 2 draws

Obtain a bode magnitude plot for the transfer function, Q. A bandpass filte...

Q. A bandpass filter circuit is shown in Figure. Develop a PSpice program and use PROBE to obtain a Bode magnitude plot for the transfer function ¯H(f) = ¯Vout/ ¯Vin for frequency

Basic characteristics and operation of mosfet, Q. Basic Characteristics and...

Q. Basic Characteristics and Operation of MOSFET ? In Figure the gate-to-source voltage is set to zero volts by the direct connection from one terminal to the other, and a volt

Discuss merits and demerits of macro over procedures, Discuss merits and de...

Discuss merits and demerits of Macro over procedures.  The MACRO directive informs assembler the starting of a macro which is used with ENDM directive to enclose a macro. The

Define abcd propagation , ABCD propagation of an optical ray through a s...

ABCD propagation of an optical ray through a system can be described by a straightforward two by two  matrix. In ray optics, the feature of a system is known by the correspondin

How does expert system works, How does Expert system works? System uses...

How does Expert system works? System uses a rule base and an inference engine together to simulate human reasoning whenever analysing a problem and arriving at a conclusion. To

Determine the antennas radiated power, Q. A transmitter is connected to an ...

Q. A transmitter is connected to an antenna by a transmission line for which ¯ Z 0 = R 0 = 5 0 . The transmitter source impedance is matched to the line, but the antenna is kno

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd