Zener diode as voltage regulator tutorial basic electronics tutorials. A specific diode s vf depends on what semiconductor material its made out of. Zener diode lab viva questions and answers pdf free download. In the reverse biased mode zener diode has large breakdown voltage and though the current increases the voltage remains constant. Characteristics of pn junction diode and zener diode. Zener breakdown voltage should be approximately close to the desired voltage we want. Write down all circuit equations and simplify as much as possible 2. Replace the procedure in experiment 3 with the following procedure 1 measure the voltage and current through a signal diode use a 1n4148 from your graymark kit these are also available in the instrument room. In case of junction diodes, there are two types of characteristics, forward and reverse characteristics.
The voltampere characteristics of a diode explained by the following equations. Texas instruments transistor and diode databook 1st ed 1973 datasheets for diodes from 1n251 on and transistors from 2n117 on acrobat 7 pdf 34. We operate a zener diode in reverse biased conditions, and this diode does not get damaged even when the voltage across this exceeds the reverse breakdown voltage. Experiment 16 the pn junction university college dublin. The maximum forward current is limited by heatdissipation ability of the diode. To construct a zener voltage regulator and experimentally determine the range over which the zener maintains a constant output voltage. Dec 16, 2012 and the best rectifier is fullwave rectifier. Zener breakdown voltage should be approximately close to the desired voltage. Each diode was investigated by plotting the iv curve using a precision sourcemeasurement unit b2902a and a laptop with the corresponding quick iv measurement software installed. Part bfrom both experiment we can conclude the diode can become insulator when inreverse biased and also can be a conductor when in forward biased because thatstime the resistance become low and can make the current easily flow trough diode. Determining the value of the reversebias saturation current determining the value of the emission coefficient 2 principles the diode is a device formed from a junction of ntype and ptype semiconductor. Zener diode applications chapter 3 overview zener diodes zener characteristics zener diodes diode types rectifier zener lower vz due to more heavily.
In forward bias condition, current is constant until certain voltage is reached. Diode, resistor, variable dc power supply, milliammeter, voltmeter, rheostat and wire. A semiconductor diode is prepared by joining p and n sections of a semi conducting material like germanium or silicon. Scribd is the worlds largest social reading and publishing site. Diode types the zener diode utilises the same basic structure as an ordinary diode, but the concept of operation of the reverse breakdown effects are not normally wanted or used for normal diode. Conduct the experiment for obtaining the forward bias vi characteristics of the given diode. If a diode is fully conducting, it can usually be assumed that the voltage across it is the forward voltage rating. This series of zener diodes is offered in the convenient, surface mount plastic sot23 package. Electrostatic analysis of a pn diode pnjuntion diode. Zener diode characteristics in reverse direction however there is a very small leakage current between 0v an the zener voltage i.
These devices are designed to provide voltage regulation with minimum space requirement. Lab 5, diodes 2 we are interested in the solid state pn junction diode which has the following type of characteristics. To study and measure the effects of forward and reverse bias on the zener diode. To study and measure the effects of forward and reverse bias on the zener diode current. Connections are made as shown in the circuit diagram. A diode is simply a pn junction see introduction into semiconductor physics with the following characteristics. Two types of reverse breakdowns occur in zener diode. Its characteristics are otherwise very similar to common diodes. Zener diode characteristics in the forward region, the zener diode acts like a regular silicon diode, with a 0. Pdf v i characteristics of diode through computer researchgate. Simulator procedure as performed through the online labs select the characteristics of diode from the drop down list.
We will first consider the iv characteristic curve of a standard diode that we can use in the classroom. We are going to learn about an experiment to find out the zener breakdown voltage and draw the characteristics of zener diode. Characteristics of zener diode dhanalakshmi college of. Pn junction diode experiment forward characteristics by. A graph showing the variation of voltage applied across the terminals of a diode to the corresponding current is called characteristics of a diode. Jan, 2015 pn junction diode characteristics lab expriment 1. All books are in clear copy here, and all files are secure so dont worry about it. The zener diode is used in its reverse bias or reverse breakdown mode, i.
A typical zener diode characteristic is shown in fig. But simulation doesnt necessarily give the true effect of any experiment as the simulation depends. For instance, to invoke a 1n4148 diode from the builtin library, we use a command of the type dxxx a c d1n4148. Correspondingly, is there a way we could determine the type of breakdown action from experimental measurements on a zener diode. It is also required to obtain the capacitancevoltage characteristics of the diode. Properties of junctions zener diode characteristics. The polarity of the voltage source is such that the photodiode is reversed biased. You may use either of three methods to measure the vi characteristics. Characteristics of a diode 1 objects of the experiment studying the characteristics of a diode. Read online zener diodes vishay intertechnology book pdf free download link book now. Experimently find out whether the given diode is made of germanium or silicon. Diode characteristics 2012 summary this experiment was set up to investigate the different properties and characteristics of several different types of diode. We have also learned about diffusion current, depletion region.
In view of the coronavirus pandemic, we are making live classes and video classes completely free to prevent interruption in studies. A zener diode is constructed for operation in the reverse breakdown re gion. It is acting as normal diode while forward biasing. Pn junction diode characteristics experiment complete with readings. Diodes and diode circuits tlt8016 basic analog circuits 20052006 2 3. Definition ptype semiconductor is suitably joined to ntype semiconductor,to conduct surface is called pn junction. Diode iv characteristics the iv graph for a nonideal diode is shown in figure 2, along with an ideal approximation to accommodate the nonzero threshold voltage. To extract a linear model for the diode from the experimental iv curve. Reverse dc power supply polarity for reverse bias repeat the above procedure for the different values of supply voltage for reverse bias draw vi characteristics for forward bias and reverse bias in one graph. The diodes symbol is an arrow with a bar, the arrow indicates the direction in which positive forward. In the forward biased mode the zener diode operates as a pn diode. In this tutorial, we will examine the use of zener diode in pspice and learn about editing the properties of devices this tutorial is written with the assumption that you know how to do all of the basic things in. For correct voltage regulation, we need to find out precisely what voltage should be across the zener diode. Breakdown voltage is also known as zener knee voltage.
A semiconductor diode is prepared by joining p and n sections of a semi conducting. The objective of this experiment is to become familiar with the properties and uses of diodes. The value of the resistance is the inverse of the slope of the iv characteristics of the zener diode d all of the mentioned. In the case of normal diodes the diode damages at the break down voltage. Zener diode vi characteristics reverse characteristics of zener diode ideal zener diode equivalent circuit model practical zener diode equivalent circuit model in rbr. The zener diode is a particular type of diode that solves this problem. Experiment 6, photodiode and phototransistor current measurements.
The contact surface between the layers of ptype and ntype semiconductor pieces plated together so as. It also permits the current to flow in the reverse direction when the voltage is above a certain value known as the breakdown voltage. Pn junction diode and its characteristics in chapter 1 understanding the pn junction, we have seen how a pn junction is formed from a ptype and ntype semiconductor. Zener diode is a pn junction diode specially designed to. Zener diode, resistors, power supply, multi meter circuit diagram. Observation of characteristics of a zener diode debangshu mukherjee bs. Zener diodes vishay intertechnology pdf book manual. You diodes will use the bit bucket breadboarding system to build and test several dc and ac diode circuits. The zener diode working principles and its various. Diode circuits and applications technology innovation and. Definition a diode is a twoterminal electronic component that conducts electric current in only one direction. Zener diodes are normal pn junction diodes operating in a reverse biased condition.
The diode will be easier to understand if we compare the diode to another two terminal device we know and love the resistor. You can check out and keep the portable breadboards, vb106 or vb108, from the 111lab for yourself only one each please this is the first of three labs on basic semiconductor components. The analysis is very similar to that of a metalsemiconductor junction. Zener cards experiment software free download zener. Plot a graph with reverse voltage along x axis and reverse current along y axis. When the voltage across the terminals is reversed and the potential reaches the zener voltage or knee, the junction will break down and current will flow in the reverse direction a desired characteristic. Ppt zener diode applications powerpoint presentation. To draw the characteristic curve of a zener diode and to. Zero bias no external voltage potential is applied to the pn junction diode. April 7, 20 introduction a zener diode is a pn junction that has been specially made to have a reverse voltage breakdown at a specific voltage. A free powerpoint ppt presentation displayed as a flash slide show on id. Expt no 3 characteristics of zener diode and design a simple zener voltage regulator. Zener diode zener diode theory of operation zener diode datasheet specs zener diode circuits other diodes. By adjusting the rheostat, voltmeter reading is increased from 0 and in each time note the corresponding reading in milliammeter.
This was a bad thing before the whole avalanche breakdown, large current. The zener diode specially made to have a reverse voltage breakdown at a specific voltage. Lab experiment related theory available in following books. The experiments in this laboratory exercise will provide an introduction to. To study the forward and reverse bias characteristics of diode and zener diode. It has a particular voltage known as break down voltage, at which the diode break downs while reverse biased. Experiment 3 recording the current voltage characteristics. Experiment 16 the pn junction introduction in this experiment on the physics of the pn junction, a determination is made of both the universal constant ek i. Diodes and transistors pdf 28p this note covers the following topics. Let us learn about this exciting and unique kind of diode. A key difference is that a pn diode contains two depletion regions of opposite type.
Basic electronics notes on vi characteristics of zener. The electronhole pairs are free to diffuse or wander throughout the bulk of the photodiode until they. Under forward bias, it needs a small voltage to conduct. While performing the experiment do not exceed the ratings of the transistor. Zener cards experiment, free zener cards experiment software downloads, page 3. To analyse the diode as a part of electronic circuits. A zener diode is a special kind of diode which allows current to flow in the forward direction in the same manner as an ideal diode, but will also permit it to flow in the reverse direction when the voltage is above a certain value known as the breakdown voltage, zener knee voltage or zener voltage. In this experiment also we know the how to differentiate. A diode, in electronics, is a two terminal electronic component with an asymmetric transfer characteristics, with low resistance to current flow in one direction and high resistance to current flow in the other direction. Diode experiment guide view experiment properties of semiconductor junction diodes and their applications view experiment diode background information.
The graph shows the reverse vi characteristics of the given pn junction diode. Experiment 8 diodes rensselaer polytechnic institute. Full practical zener diode with readings download pdf. Lab report zener diod free download as powerpoint presentation. This paper shows the vi characteristics of diode through pc that records the different readings of.
Zener diode experiment viva questions with answers characteristics mcqs interview questions. Pdf zener effect is discussed focusing on the energyband theory of solids, especially. Use the diode equation for that state to solve the circuit equations and find i d and v d 3. Equivalent circuit of zener diode 1 for ideal diode. To draw the reverse characteristic curve of a zener diode and to find its reverse breakdown voltage. Zener diode characteristics the figure shows, the forward characteristics is same as that of ordinary forward biased junction diode. To get familiar with working knowledge of the following instruments. While doing the experiment, do not exceed the rating of the diode. Basic semiconductor physics, diodes, the nonlinear diode model, load line analysis, large signal diode models, offset diode model, transistors, large signal bjt model, load line analysis, small signal model and transistor amplification. Diode circuits tutorial pdf 25p this note covers the following topics. The complete vi characteristics of zener diode is as shown in figure. Zener diode is a pn junction diode specially designed to operate in the reverse biased mode. Click here to learn the concepts of special diodes.
The pn junction and the diode effect, current in the diode, the pn diode as a circuit element, circuit applications of ordinary diodes, power supplies, power supply filtering, split power supply, diode gate, diode protection. A multimeter with a diode setting can be used to measure the minimum of a diode s forward voltage drop. Measure voltage across diode and current through diode. Working of the zener diode is similar to a pn junction diode in forward biased condition, but the uniqueness lies in the fact that it can also conduct when it is connected in reverse bias above its threshold breakdown voltage. Jan 02, 2019 we are going to learn about an experiment to find out the zener breakdown voltage and draw the characteristics of zener diode. To draw the characteristic curve of a zener diode and to determine its reverse breakdown voltage aim to draw the characteristic curve of a zener diode and to determine its reverse breakdown voltage. A zener diode is a heavily doped silicon crystal diode which allows current to flow in the forward direction in the same manner as an ideal diode. Feb 15, 2016 class 12th physics experiment to determine iv characteristics of a pn junction diode in forward bias donate with paytm. Apparatus a zener diode with small reverse breakdown voltage of about 6 volts, i. In this region the voltage across zener diode remains constant but current changes depending on the supply voltage.
To get familiar with working knowledge of the following. A special type of pn junction diode that operates in reverse biased mode, more specifically in breakdown region is known as zener diode the doping level of the zener diode is somewhat higher than the normal pn junction diode. They are well suited for applications such as cellular phones, hand held portables, and high density pc boards. Recipe for solving diode circuits state of diode is unknown before solving the circuit 1. Zener diodes are heavily doped than ordinary diodes. A zener diode is a type of diode that allows current to flow in the conventional manner from its anode to its cathode i. Zener diodes when we first talked about practical diodes, it was mentioned that a parameter associated with the diode in the reverse bias region was the breakdown voltage, v br, also known as the peakinverse voltage piv.
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