The power gain of the common collector amplifier is medium. Pn junctions consist of two semiconductor regions of opposite type. Regions of operations and measurements forward active saturation. Here we will describe the system characteristics of the bjt. The purpose of this experiment is to measure the current gain of an npn transistor. An npn transistor has an n type emitter, a p type base and an n type collector while a pnp transistor. Of the six variables v cb, v be, v ce, i c, i b, and i. Pn junction diode technology innovation and incubation centre. Design the amplifier for voltage gain a v to be at a minimum of 100 vv and choose resistor values of r c and r e by calculation. Shahram marivani bipolar junction transistor characteristics. A pnjunction diode is formed when a ptype semiconductor is fused to an ntype semiconductor creating a potential barrier voltage across the diode junction the effect described in the previous tutorial is achieved without any external voltage being applied to the actual pn junction resulting in the junction being in a state of equilibrium. To study the input and output characteristics of an npn transistor in common. Jan 23, 2015 npn transistor is one of the bipolar junction transistor bjt types. Npn transistor is one of the bipolar junction transistor bjt types.
We will use dmm to measure these voltages and currents for different characteristics. Experiment 6 transistors as amplifiers and switches. To study the characteristics of a common emitter npn or pnp. Lab 6 common emitter iv characteristics of a npn bipolar junction. A voltage v e then leaves the emitter and enters the circuit of which the npn transistor is a component. A transistor is a semiconductor device used to amplify or switch electronic signals and electrical power. They are also called pn diodes in analogy with vacuum diodes. Having a good grasp of the physics of the bjt is key to understanding its operation and applications.
In an npn transistor, the three terminals are named the emitter first nblock, the. Connect the m3500 npn1on lab chip 2 as shown in fig. The flowing of these electrons from emitter to collector forms the current flow in the. A pn junction is the metallurgical boundary between the n and pregions of a semiconductor crystal. Connect the transistor test circuit as shown in figure 2. The transistor we will use is the 2n4401, an npn device. To draw the characteristic curve of a zener diode and to determine its reverse break down. Bipolar junction transistors bjt general configuration and definitions the transistor is the main building block element of electronics. May 14, 2019 the bipolar junction transistor or simply bjt is a three layer, three terminal and two junction semiconductor device. The 2n2219a is a general purpose, npn transistor similar to the pn2222. The transistor will operate as an amplifier or other linear circuit if the transistor is biased into the linear region. Objectives the commonemitter terminal characteristics of a bipolar junction transistors bjts will be determined experimentally using a commercial transistor curve tracer. Physics lab manualncert solutions class 12 physics sample papers. All of the above ratings are subject to change with temperature variations.
The ce configuration is widely used in amplifier circuits because it provides voltage gain as well as. To study the input and output characteristics of a transistor common emitter configuration. Npn transistor circuit working, characteristics, applications. A bipolar junction transistor bipolar transistor or bjt is a type of transistor that uses both electrons and holes as charge carriers. Transistors find many and varied uses in our daily life ranging from gas lighter and toys to. A voltage v e then leaves the emitter and enters the circuit of which the npn. Hey everyone do subscribe my channel and feel concept of physics would make you all fall in love with physics you can follow me on unacademy too s. The data will then be compared to equivalent models available in pspice. Measure the voltage gain of the amplifier to see how it compares with your. An npn transistor may have either a common base cb or a common emitter ce configuration, each with its own distinct inputs and outputs. If, for example, the operating temperature is above that stated for the ratings, the ratings must be decreased. Transistor is made by using of 2 pn junction diode. Biasing the baseemitter junction combine the previous two circuits so that baseemitter junction is in the forward direction so for a npn transistor we would place the battery thus. Theory bipolar transistors are semiconductor devices that contain two pn junctions, similar to the junctions in diodes.
This experiment measures the output characteristic. The word transistor is a combination of the two words trans fer var istor which describes their mode of operation way back in their early days of electronics development. After reading the following elementary introduction to the bjt, be sure to read sedra and smith, microelectronic circuits 4th edition, ss4 pp. During the experiment, we tried to increase the temperature by connecting. C for generalpurpose discrete npn bjt, 2n3904, used in this laboratory experiment. The video covers following topics structure of silicon atom, doping, n type doping, p type doping, working of diode, working of npn transistor and dual stage amplification. Junction field effect transistor jfet the single channel junction fieldeffect transistor jfet is probably the simplest transistor available. This experiment is designed to introduce you to the bipolar junction transistor bjt characteristics that describe the commonemitter configuration. The common collector amplifier has high input impedance and low output impedance. Bipolar junction transistor characteristics page 4 5. Transistor is the very important components in electronics system. A bipolar transistor allows a small current injected at one of its terminals to control a much larger current flowing between two other terminals, making the device. Theory a transistor is really two diodes arranged back to back as in figure 1 where there is an np junction between the emitter and the base and a pn junction between the base and the collector.
Since an integrated circuit is constructed primarily from dozens to even millions of transistors formed from a single, thin silicon crystal, it might be interesting and instructive to. Haileselassie and kou vue 111420 elc eng 330 electronics i fall 201 2. Jul 14, 2016 the video covers following topics structure of silicon atom, doping, n type doping, p type doping, working of diode, working of npn transistor and dual stage amplification. Bipolar junction transistor physics and radioelectronics. A pn junction diode is formed when a ptype semiconductor is fused to an ntype semiconductor creating a potential barrier voltage across the diode junction the effect described in the previous tutorial is achieved without any external voltage being applied to the actual pn junction resulting in the junction being in a state of equilibrium. Set the dc voltage v b to zero volt and v cc to 10 v. Bjts use two junctions between two semiconductor types, ntype and ptype. Experiment 5 common emitter characteristics of npn 31 voltage v ce and output current is collector current i c. The pn junction is a versatile element, which can be used as a. The bipolar junction transistor bjt, conceived by william shockley and first realized by.
A voltage or current applied to one pair of the transistors terminals changes the current through another pair of. Also, read online materials on transistors, particularly npn bipolar junction transistors bjt because that is the type of transistor to be studied in the experiment 2n2222. Experiment 6 transistors as amplifiers and switches our final topic of the term is an introduction to the transistor as a discrete circuit element. In the npn, electrons are injected from the forwardbiased emitter into the thin base region where, as. The main objective of this experiment is to measure and graph the collector characteristic curves for a bipolar junction transistor.
Working of transistor as a switch npn and pnp transistors. To study the characteristics of commonemitter npn or pnp transistor and to find out the values of current and voltage gains. Measure the voltage of the collector from the bipolar junction npn transistor. Wire up an npn transistor as an emitter follower figure 8. With the bias setup shown, the positive terminal of the battery repels the emitter holes toward the. A common base and a common collector amplifier will be designed and tested. Collector to emitter junction is reverse biased and base to emitter junction is forward biased. It is strongly suggested that you read and understand the section on bjt physics before beginning this. Bipolar junction transistor characterization 1 objective the bjt was invented in 1948 by william shockley at bell labs, and became the. I c v be characteristic of the bipolar junction transistor. Pn junction diode technology innovation and incubation. The baseemitter junction is biased in the forward direction however, the basecollector junction is in the reverse direction so no current flows. Bipolar junction transistors also known as bjts can be used as an amplifier, filter, rectifier, oscillator, or even a switch, which we cover an example in the first section. We will be able to create the circuit and using the data with only using the computer application called multisim.
There are two basic types of bipolar transistor construction, pnp and npn, which basically describes the physical arrangement of the ptype and ntype semiconductor materials from which they are. Jun 21, 2018 transistor is the very important components in electronics system. Since an integrated circuit is constructed primarily from dozens to even millions of transistors formed from a single, thin silicon crystal, it. In commonemitter circuit of a transistor, emitterbase make input section and emitter collector make output section. In this experiment, transistor type 2n3904 is used. Bjt characteristics theory the transistor is a two junction, three terminal semiconductor device which has three regions namely the emitter region, the base region, and the collector region. It is composed of semiconductor material with at least three terminals for connection to an external circuit.
To fully describe the behavior of a transistor with cc configuration, we need two set of characteristics input characteristics and output characteristics. In this tutorial, we will discuss how to generate a typical iv curve for a bipolar junction transistor bjt in multisim. Dec 28, 2017 hey everyone do subscribe my channel and feel concept of physics would make you all fall in love with physics you can follow me on unacademy too s. Unipolar transistors, such as fieldeffect transistors, use only one kind of charge carrier.
The purpose of this laboratory is to become familiar with the d. The lower keithley is used to supply vbe and the upper keithley is used to supply vce. It is a semiconductor device and it comes in two general types. Physics 120 lab 8 2019 bipolar junction transistors. An npn transistor, a three volt battery, a 30 volt battery, two high resistance. Almost in many of the applications these transistors are used for two basic functions such as switching and amplification. Name quantity name quantity 1 transistor npn bc 107 1one no.
The frequency response will be measured and the dc voltages will be compared to calculated values. Some of the applications use a power transistor as switching device, at that time it may necessary to use another signal level transistor to drive the high power transistor. The end result is that if we bias the transistor so that its baseemitter pn junction is forward biased base about 0. A transistor is a linear semiconductor device that can control a larger current through one of its terminals with a low power applied electrical signal, which could be either a current, as in the case of a bipolar junction transistor bjt, or a voltage, when it is called a fieldeffect transistor. The npn transistor consists of two ntype semiconductor materials and they are separated by a thin layer of ptype semiconductor. Both npn and pnp transistors can be used as switches.
Mainly transistors are used for the switching purpose. There are two varieties, the pnp and the npn, but we will focus on the more common npn configuration. Such junctions show a pronounced rectifying behavior. Experiment 8 bipolar transistors objective to characterize an npn bipolar transistor, and measure the dc operating point and the ac performance of a single transistor amplifier. The bipolar junction transistor is the realworld component of this sandwich. Experiment 17 to study the characteristics of a npn or pnp transistor. The dc voltage and current variables associated with an npn bjt are shown in figure 78. With the bias setup shown, the positive terminal of the battery repels the emitter holes toward the base, while the negative terminal drives. Experiment 6 bipolar junction transistor characteristics. The experiment examines the properties of an npntransistor on the basis of its characteristics. A more useful semiconductor device is a bipolar junction transistor bjt. Transistor acts like an open switch between collector and emitter i. Here the majority charge carriers are the electrons.
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