Smith department of eecs university of california, berkeley eecs 105 spring 2004, lecture 22 prof. Bipolar junction transistors, bjt in active mode, a simple bjt circuit, ebersmoll model for a pnp transistor, ebersmoll model, ic vce characteristics. In summary, during this lesson i introduced the bipolar junction transistor. In an npn transistor, a thin and lightly doped ptype base is sandwiched between a heavily doped ntype emitter and another ntype collector. In this first transistor lecture, well spend time applying our familiar semiconductor. In this lecture, well introduce one of the fundamental analog devices. Bipolar junction transistors tlt8016 basic analog circuits 20052007 12 4. The operation of the transistor is very dependent on the degree of doping of the various parts of the. Basics of transistor bias point and the class of amplifier operation duration. The transistor is the main building block element of electronics it is a semiconductor device it is a three terminal device two basic families of transistors are. One way to look at a bjt transistor is two backtoback diodes, has very different characteristics. Lecture 2 bipolar junction transistor fabrication youtube.
Download pdf of bipolar junction transistor notes material offline reading, offline notes, free download in app, engineering class handwritten notes, exam notes, previous year questions, pdf free download. Lecture notes microelectronic devices and circuits. Sep 01, 2008 lecture series on electronics for analog signal processing i by prof. The objective of this course is to develop the ability to analyse and design electronic circuits both analog and digital, discrete and integrated. Two pn junctions are formed as a result so you have a pn junction from here to here and another pn junction from here to here. And the saturation current is a very small number, typically about 1 times 10 to the minus 15 amps. Analysis that replaces the transistor with a pair of batteries representing the two junction turn on voltages cvd model. In this chapter you will learn the physical structure of the bipolar transistor and how it works. The base current i b controls the collector current i c regions of bjt operation. Introduction to bipolar junction transistor bjt youtube. Boring analysis that removes the transistor from the circuit leaving an open circuit. Bipolar junction transistor 1 by basic electronics. Bjt physics 2 npn bipolar junction transistor bjt 3 layers of semiconductors emitter ntype, base ptype, collector ntype emitter e be junction.
Transistor as a device which transfers its resistance from high to low and by this property transistor amplifiescontrol input current signal. Bjt bipolar junction transistor construction, types and. As we learned a diode is a simple pn junction device and it has two doped region nregion and pregion when a second pn junction is formed and connected in the back to back fashion then the resulting device is formed and known as bjt bipolar junction transistor. Bipolar junction transistor bjt few most important applications of transistor are. Bipolar transistors intro video lectures created by tim feiegenbaum at north seattle community college. Upon completion of the presentation you will be able to understand. Lecture 18 pnp bipolar junction transistors bjts in this lecture you will learn. Now, we will look at something called the unipolar transistor later in this chapter, but for now, were going to focus on bipolar transistors. The bipolar junction transistor bjt is an active device. Introduction to bipolar junction transistors bjt bipolar. Lecture 3 bipolar junction transistor free download as powerpoint presentation. Bipolar junction transistors emitter p n collector base pnp transistor emitter n p base npn transistor bipolar.
A circuit simulation package will be made available as free download to enable students. Bipolar junction transistors learn about electronics. Two additional bipolar devices are the npn and the pnp and these are bipolar transistors. For the bjt to operate as an amplifier, the base emitter junction. Bipolar junction transistors bjt general configuration and definitions the transistor is the main building block element of electronics. Lecture 08 bipolar junction transistor ii transistor dc model 2 dr. As we have seen a semiconductor offers less resistance to flow of current in one direction and high resistance in another direction, we call the device made of semiconductors as a transistor. Transistor is a three terminal semiconductor device used as amplifier, switch or oscillator. The behavior of the npn transistor is determined by its two pnjunctions. Nptel provides elearning through online web and video courses various streams. In summary, during this lesson i introduced the bipolar junction transistor, a three terminal device that consists of two pn injunctions. The forward biased baseemitter be pn junction allows the majority charge carriers, the electrons, in ntype emitter to go through the pn junction to arrive at the ptype base, forming the emitter current.
In this video, the bipolar junction transistor, its different region of operation, different configurations and the working is briefly explained. Nandita dasgupta, department of electrical engineering, iit madras. Npn transistors consist of three layers of semiconductor material, okay. Bipolar junction transistor 6 video lecture by prof s. How a bjt bipolar junction transistor works its all in the doping the way a transistor works can be described with reference to fig. Aug 02, 2019 what is bipolar junction transistor, working as an amplifier and switch and their applications. A bipolar junction transistor bjt has three terminals connected to three doped semiconductor regions. Introduction of bipolar junction transistor, terminal characteristics, forward active bias, current gain. Analog circuits video course course outline this course is an introduction to amplifiers using transistors.
Collector npn transistor pnp transistor p n p n p n. A bipolar junction transistor, or bjt, is a type of transistor in which the current flow between the collector and the emitter is controlled by the amount of current that flows through the base. Structure and symbol of bipolar transistor ee105spring2008 lecture4,slide2prof. Lecture series on electronics for analog signal processing i by prof. Bipolar junction transistor bjt field effect transistor fet transistors are used in. Lecture 46 the bipolar junction transistor bjt 1 notes video. Bipolar junction transistors pdf 46p download book. Bipolar junction transistor 6 tutorial of solid state devices iit madras course by prof s. A bipolar junction transistor bjt consists of three differently doped re gions. Smith context in fridays lecture, we discussed bjts bipolar junction transistors today we will find large signal models for the bipolar junction transistor, and start exploring. Bipolar transistors intro transistors and transistor. It is a semiconductor device and it comes in two general types. Bipolar junction transistor 8 typical operation of junction transistor amplifier typically the collector current, ic, is 100 to times greater than the base current ib, depending on the type of transistor used if we take the base current ib as an input and the collector current ic as an output, then we can say that. Microelectronics online course video lectures by iit roorkee.
Here we will describe the system characteristics of the bjt. Ee5310 analog electronic circuits video course iit madras. Ee314 introduction your goal is to explain the transistor. Solid state devices lecture 18 bipolar transistors a. The invention of the bipolar transistor in 1948 ushered in a revolution in electronics. The base current i b controls the collector current i. Introduction, semiconductor, equilibrium carrier concentration, carrier transport, excess carriers, pn junction, procedure for device analysis, bipolar junction transistor bjt, metaloxidesemiconductormos junction, mos field effect transistor mosfet. Lecture 5 bipolar junction transistors enee 303 fall 2016 subscribe to view the full document. Find materials for this course in the pages linked along the left. This name is a representation for a device having transfer resistors.
Transistor action baseemitter junction is forward biased and collectorbase junction is reverse biased electrons emitted into base much more than holes since the doping of emitter is much higher magic. The twocarrier flow from 1 and 4 forms the emitter current ie. This notes consists of introduction to bjt, itw working, different transistor configuration, biasing techniques, compensation techniques etc. The operation of bipolar junction transistors forward and reverse active operations, saturation, cutoff ebersmoll. Module 3 bipolar junction transistors semiconductors module 3 pdf 3 e. Structure and symbol of bipolar transistor ee105spring 2008 lecture4, slide 2prof. Lecture32bipolar juncction transistorcontd youtube. Bjt physics 1 ee105 fall 2014 microelectronic devices and circuits prof. The bjt has two pn junctions, the base emitter junction and the base collector junction. Bjts 3 bipolar junction transistor npn bjt shown 3 terminals.
Alan doolittle lecture 12b advanced field effect transistor fet devices reading. The operation of bipolar junction transistors forward and reverse active operations, saturation, cutoff ebersmoll model small signal models ece 315 spring 2007 farhan rana cornell university bipolar transistors first bipolar transistor. Lecture 23 the bipolar junction transistor bjt video. We will begin looking at transistors with the bipolar junction transistor. Equivalent to an off state when transistor is used as a switch. Bipolar junction transistors the transistor is a threelayer semiconductor device consisting of either two n and one p type layers of material or two p and one n type layers of material. Most electrons cross the base junction and are swept into collector why. The early voltage va has a typical value of 150 volts. Smith context in fridays lecture, we discussed bjts bipolar junction transistors today we will find large signal models for the bipolar junction. Ee105 fall 2014 microelectronic devices and circuits. Bipolar junction transistors bjts the bipolar junction transistor is a semiconductor device constructed with three doped regions. The outer two regions are doped with the same polarity, while the middle region is doped with opposite polarity. The bipolar junction transistor bjt is constructed of three regions. L12 voltage transfer characteristic,bjt biasing 1 free download as powerpoint presentation.
Alan doolittle lecture 20 bipolar junction transistors bjt. Lecture 3 bipolar junction transistor bipolar junction. Introduction to bipolar junction transistor bjt slideshow. These can have the configuration of npn or pnp and the various layers can either be. It is assumed that ee314 students to which this presentation is aimed, have not a clue to how these little buggers work andor how to use them. It is a type of transistor that uses both electron and hole charge carriers. Oct 08, 2014 in this lecture, well introduce one of the fundamental analog devices. These regions essentially form two backtoback pn junctions in the same block of semiconductor material silicon. Technical feats previously requiring relatively large, mechanically fragile, powerhungry vacuum tubes were suddenly achievable with tiny, mechanically rugged, powerthrifty specks of crystalline silicon. Lecture 18 bipolar junction transistors bjts in this lecture you will learn. Radhakrishna rao, department of electrical engineering,iit madras. The type of transistor just described is a npn bipolar junction transistor schematic symbol. This course is intended for the core courses in electronics circuits taught to undergraduates in electrical and computer engineering. One can also make pnp bipolar junction transistors summary of i c as a function of v ce for a given i b.