Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Power Transistor
A power transistor is a three layer PNP or NPN semiconductor device having two junctions. Three terminals of power transistors are collector emitter and bas. The current flow in the device due to the movement of both electronic and holes hence named bipolar. Early transistor was made from germanium but most modern power transistors are made from silicon. For very high speed applications a significant minority are also now made form gallium arsenide.
Figure NPN transistor Basic structure symbol
The structure symbol of NPN transistor is shown in figure 1.4 most bipolar transistors used today are NPN because electron mobility is higher than hole mobility in semiconductors which allows greater current and faster operation. NPN transistors consist of a layer of p doped semiconductor between two N doped layers. A small current entering the base in common emitter mode is implied in the collector output.
Figure PNP Transistor basic structure symbol
It means an NPN transistor is ON when its pulled high relative to the emitter. The arrow in the NPN transistor symbol shows the direction of the conventional current flow.
PNP transistor is shown in figure PNP transistors consists of a layer of N doped semiconductor between two layers of p doped material. A small current leaving the base in common emitter mode is amplified in the collector output. It means a PNP transistor is ON when its base is pulled low relative to the emitter. The arrow in the PNP transistor shown the direction of the conventional current flow.
In power transistor the base physically located between the emitter and the collector and is made from light doped high resistivity material. A cross section view of a BJT indicates that the collector base junction has a much lager area than the emitter vase junction. The reverse bias voltage to be applied before the collector base junction breaks down. The collector base junctions is reverse biased in normal operation. The reason the emitter is heavily doped is to increase the emitter injection efficiency. It means the ration of carriers injected by the emitter to those injected by the base. For high current gain most of the carriers injected into the emitter base junction must come from the emitter. Power transistors has low current gain. It requires continuous signal to the base during ON state condition. Power transistor cannot withstand reverse voltage and application is limited to DC voltage for inverters and choppers. Power transistors are medium speed switches used for power supplies of a wide variety of electronic equipments ranging from computer peripherals to industrial equipment .
Q. Explain Thevenin and norton equivalent circuits? For a linear portion of a circuit consisting of ideal sources and linear resistors, the volt-ampere (v-i) relationship at an
shockely equation?
Once you are happy with the biasing components you will need to disable the DC simulation component and enable the SP component. (Right click the component and then select the "com
Sub Threshold The sub threshold I-V curve depends exponentially on the threshold voltage, introducing a strong reliance on any manufacturing variation that influences threshol
Energy Gap Differentiating feature between the metals, insulators, and semiconductors. Ascertains the absorption or emission spectra, the leakage current, and the intrin
What are the industrial applications of the project bcd to excess 3 code converter?
Explain Ferrimagnetic magnetic materials. Ferrimagnetic Materials: In such materials unequal magnetic dipoles are lined up anti-parallel to each other. And permeabilities are
Can I get some ideas for power system stability simulation using Matlab?
What is limitor.. how it works
Differentiate between synchronous and asynchronous types of serial communication. Serial data communication uses two fundamental types as, synchronous and asynchronous. With
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!
whatsapp: +1-415-670-9521
Phone: +1-415-670-9521
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd