Npn bjt with forward-biased, Electrical Engineering

NPN BJT with forward-biased:

An NPN transistor can be referred as two diodes along with a shared anode. In common operation, the base-emitter junction is forward biased and the base-collector junction is reverse biased. In an NPN transistor, for instance, while a positive voltage is applied to the base-emitter junction, the equilibrium among the thermally generated carriers and the repelling electric field of the depletion region turns unbalanced, permitting thermally excited electrons to inject into the base region. These electrons wander or "diffuse" via the base from the region of high concentration near the emitter in the direction of the region of low concentration near the collector. The electrons in the base are termed as minority carriers since the base is doped p-type that would make holes the majority carrier in the base.

To minimize the percentage (%) of carriers which recombine before arriving at the collector-base junction, the base region of transistor must be thin enough which carriers can diffuse across it in much less time than as compared to the semiconductor's minority carrier lifetime. Particularly, the thickness of the base has to be much less than diffusion length of the electrons. The collector-base junction is reverse-biased, and thus the little electron injection takes place from the collector to the base, but electrons that diffuse by the base towards the collector are swept into the collector via the electric field in the depletion region of the collector-base junction. The thin shared base and asymmetric collector-emitter doping is what distinguishes a bipolar transistor from two separate and oppositely biased diodes that are connected in series.

Posted Date: 1/10/2013 6:36:48 AM | Location : United States







Related Discussions:- Npn bjt with forward-biased, Assignment Help, Ask Question on Npn bjt with forward-biased, Get Answer, Expert's Help, Npn bjt with forward-biased Discussions

Write discussion on Npn bjt with forward-biased
Your posts are moderated
Related Questions
Competition and Non-conventional energy: Competition: The tariff policy bolsters competition through making it mandatory for a distribution licensee to procure power by

pls how can i stat up building wind turbine

Q. Write a note on feedback of emitter follower? The emitter follower can be seen to be an example of negative feedback when the relationship is put in the form

Complete Instruction Set of 8085 Microprocessor There are  total 256 instructions in  8085 microprocessor. These instructions are classified  into  seven categories  according

Magnetic materials (A) provide path to magnetic flux. (B) are good insulators. (C) are semiconductors. (D) None. Ans: Magnetic materials provide path to

Q. Explain about Floating Point Numbers? The IEEE Standard 754 floating point is the most common representation today for real numbers on computers. There are numerous ways

Static Electricity : This is produced when two substances are rubbed together; the substances may be solids, liquids, or gases. Typical sources of static electricity are: i) dr

Q. A three-phase ac motor, used to drive a draft fan, is connected to a 60-Hz voltage supply. At noload, the speed is 1188 r/min; at full load, the speed drops to 1128 r/min. (a

Ballistic galvanometer

Name some application where you see use of serial communication. Within the world of serial communications, there are two different equipments are: DTE stand for Data Termin