By relating these junctions to a diode model the pnp bjt may be modeled. We also learnt that the junctions of the bipolar transistor can be biased in one of three different ways common base, common emitter. For this test, you can view the transistor as two diodes connected as shown in below figure for both npn and pnp transistors. Bipolar junction transistor use to control electric current npn or pnp, along with biasing modescurrent, voltage dividing, double base. Multisim tutorial using bipolar transistor circuit. If you are finding the complete basic transistor notes pdf then you are at right place. The npn transistor in the previous tutorial we saw that the standard bipolar transistor or bjt, comes in two basic forms. How to use bjt bipolar junction transistor beginners tutorial.
This is very similar to the graphical approach used with diodes, but now we have three possible points where something could be happening base, emitter, collector. You need to look for a medium power pnp bjt that is specified near 600ma. In pnp transistor this arrow indicates as pointing in and the current direction in pnp is completely opposite to the npn transistor. The name bipolar indicates that two types of charge carriers are involved in the working of a bjt. The circuit symbols for both the npn and pnp bjt are below. It is a semiconductor device and it comes in two general types. Figure 1 bipolar junction transistors bjt ntype npn, and ptype pnp a bipolar transistor consists of three pins. A digital multimeter can be used as a fast and simple way to check a transistor for open or shorted junctions. Ic is the current out of the collector of the transistor and ib is the current out. An npn negativepositivenegative type and a pnp positivenegativepositive type the most commonly used transistor configuration is the npn transistor. Here, we introduce basic operating guidelines for bipolar transistors and outlines of these circuits.
Pnp transistors can also be used as switching devices and an example of a pnp transistor switch is shown below. What are transistors types of transistors npn transistor pnp transistor construction and working of bjt configuration of bjt. Pnp transistor tutorial the bipolar pnp transistor. The pnp transistor has very similar characteristics to their npn bipolar cousins, except that the polarities or biasing of the current and voltage directions are reversed for any one of the possible three configurations looked at in the first tutorial, common base, common emitter and common collector. The operation of a pnp transistor can be explained by having a look at the following figure, in which emitterbase junction is forward biased and collectorbase.
Pnp highside transistor switching with microcontroller. Digging even deeper into transistor types, there are actually two versions of the bjt. The npn transistor is a bipolar junction transistor mainly used for amplification and switching. A bipolar junction transistor is made up of three pieces of silicon. The humble transistor q1 emitter e collector c base b. Npn transistor tutorial the bipolar npn transistor. The three layers are called the emitter, base and collector. Lecture 7 bipolar junction transistors bjts guyeon wei division of engineering and applied sciences. Bjt comes in two types called npn transistor and pnp transistor. In this tutorial, well look at the npn transistor, how it works, circuit diagram, output characteristics curve, and applications.
Here the bjt bipolar junction transistor is discussed. A pnp transistor operates in a similar manner to a npn bjt, expect. It is solid state device that flows current in two terminals, i. Bipolar junction transistor npn bjt shown 3 terminals. The two junctions are termed the baseemitter junction. Dont base your understanding of a transistors operation on that model and. Free packages are available maximum ratings rating symbol value unit collector.
The construction and circuit symbols for both the npn and pnp bipolar transistor are given above with the arrow in the circuit symbol always showing the direction. If the transistor is a pnp, then the arrow points to the base of the transistor, otherwise it points to the output. In this tutorial well focus on the bjt, because its slightly easier to understand. How to use bjt bipolar junction transistor beginners.
Once in the base, the holes combine with base electrons. The pnp transistor the pnp transistor is the exact opposite to the npn transistor device we looked at in the previous tutorial. The construction and terminal voltages for an npn transistor are shown above. Bipolar junction transistors bjt general configuration and definitions the transistor is the main building block element of electronics. Pnp highside transistor switching with microcontroller duplicate ask question asked 3 years. The number of electrons diffused in the base region is more the number of holes diffused in emitter region. A bipolar junction transistor bjt is a three terminal circuit or device that amplifies flow of current.
Includes details of bjt device operation which is not covered in this course. This is a quick tutorial for teaching students of elec 2210 how to use multisim for bipolar transistor circuit simulation. The previous module was devoted to measuring the characteristics of a transistor. Almost in many of the applications these transistors are used for two basic functions such as switching and amplification. Basically, in this type of transistor construction the two diodes are reversed with respect to the npn type giving a positivenegativepositive configuration, with the arrow which also defines the emitter terminal this time. In particular, you measured the amplification parameter bic ib b is also known as hfe on your digital multimeter. There are several kinds of transistors available, e. A bipolar junction transistor is a three layer npn or pnp semiconductor device.
The n and the p refer to whether the area of semiconductor silicon is doped negatively or positively. The humble transistor q1 emitter e collector c base b transistor basics emitter to base junction is forward biased normally collector to base junction is reverse biased normally. The name bipolar came from the fact that the device operation depends on movement of charge carriers with both polarities holes and electrons. It is written such that no prior multisim knowledge is required. We also learnt that the transistor junctions can be biased in one of three. Determine the collector current and collector voltage of the. The symbol of the transistor has an arrow on the emitter. Basic electronics transistor configurations tutorialspoint. Pnp bipolar junction transistor under dc active bias mode with added ac modulation.
Depending on what is added to the silicon, it will be either ntype or ptype. Electronics tutorial about the pnp transistor, the pnp transistor as a switch and how the pnp transistor works including its common emitter configuration. Here we share with you the basics of transistor pdf. An npn transistor has a piece of ptype silicon the base sandwiched between two pieces of ntype the collector and emitter. The arrows of pnp transistor symbol the direction of current flow when the device is. The symbols used in circuit diagrams for npn and pnp transistors are shown below. Introduction to bjt bipolar junction transistor the. The middle section base is narrow and one of the other two. An analysis of a pnp bjt circuit determine the collector current and collector voltage of the bjt in the circuit below. Transistor transistors for beginners in electronics. Bjt physical configuration each transistor looks like two backtoback diodes, but each behaves much differently. Basic electronics transistors after having a good knowledge on the working of the diode, which is a single pn junction, let us try to connect two pn junctions which make a new component call.
Introduction to npn transistor the engineering projects. Basic electronics transistor configurations a transistor has 3 terminals, the emitter, the base and the collector. The bipolar junction transistor or simply bjt is a three layer, three terminal and two junction semiconductor device. An npn transistor consists of two semiconductor junctions that have a thin pdoped anode region and pnp transistor also consists of two semiconductor junctions that have a thin n doped cathode region. Introduction to the bjt before going on with the tutorial, let us agree that we are going to discuss one among many other configurations of. Here we will describe the system characteristics of the bjt. It is a bipolar device where conduction is carried out by both charge carriers i.
For example, the doping concentrations in the collector, base and emitter may. In the previous tutorial we saw that the standard bipolar transistor or bjt, comes in two basic forms. Bipolar transistors are available at mouser electronics from industry leading manufacturers. In a pnp transistor, the type of the layers are reversed. Bjt bipolar junction transistor are widely used an amplifier, switch. The arrow for bjt transistors is always located on the emitter terminal and also it indicates the direction of conventional current flow.
Contents 1 bipolar junction transistor model 2 2 the ideal bipolar junction transistor 3. Electrons behave as a minority carrier in the base region. Pnp transistor is another type of bipolar junction transistor bjt. The purpose of this activity is to investigate the collector current, i c vs. Yet another pnp bjt large signal model this looks like a diode between base and emitter and the equivalent circuit. Bjts are of two types namely npn and pnp based on doping types of the three main terminals. The construction and circuit symbols for both the pnp and npn bipolar transistor are given above with the arrow in the circuit symbol always showing the. Bipolar junction transistor operationtypesapplications. Working of transistor as a switch npn and pnp transistors. Using these 3 terminals the transistor can be connected in a circuit with one terminal co. Bjt characteristic curves it is sometimes helpful to view the characteristic curves of the transistor in graphical form. You can always remember that the arrow points at the n material. We also learnt that the transistor junctions can be biased in one of. The interaction between the forward and reversebiased junctions in a pnp transistor is very similar to that in an npn transistor, except that in the pnp transistor, the majority current carriers are holes.
In the pnp transistor shown in figure 4, the positive voltage on the emitter repels the holes toward the base. The kit of parts the student has will contain a number of transistors ideally both npn and pnp devices of various types. An npn negativepositivenegative type and a pnp positivenegativepositive type, with the most commonly used transistor type being the npn transistor. Pnp transistor circuit characteristics, working, applications.
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