Zener diodes are a special type of semiconductor diode devices that allow current to flow in one direction only that also allow current to flow in the opposite direction, but only when exposed to enough voltage. Two types of reverse breakdown in a zener diode are avalanche and zener. They are designed to breakdown in a reliable and nondestructive way so that. The adobe flash plugin is needed to view this content. There are many circuits that use zener diodes, ranging from very simple zener diode circuits, up to far more complicated ones.
Ppt zener diode applications powerpoint presentation, free. Ppt zener diode applications powerpoint presentation free to. The circuit schematic symbol of a diode is shown in figure 5. This was a bad thing before the whole avalanche breakdown, large current. An avalanche diode is a one kind of diode that is designed to experience an avalanche breakdown at a particular reverse bias voltage. Ee40 lec 18ee40 lec 18 diode circuitsdiode circuits reading chap 10 of hamblereading. The color of light emitted by an led is determined by the type of material used in doping. The resistance depends on the amount of current i d in the diode. Zener diodes as voltage regulators a circuit diagram symbol for a zener diode. Clipping calculating resistance zener diodes the zener diode will conduct in reverse bias once the voltage exceeds the zener voltage, v z. Zener diode charceteristics voltage after breakdown is also called zener. The zener diode working principles and its various.
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. The hot carriers then lose energy by collisions with the semiconductor lattice before reaching the oxide layer and cannot be trapped there. Zener diode, resistors, power supply, multi meter circuit diagram. Diodes and transistors university of california, berkeley. Zener diodes or voltage reference diodes are used in a variety of circuits to enable them to provide a voltage reference.
In this tutorial, we will learn about different types of diodes. 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. The worst case situation occurs when vin is at the maximum value and the load current is at the minimum value as that results in the highest current through the zener diode. Zener diode is used as shunt voltage regulator for regulating voltage across small loads. In electronics, a diode is a twoterminal device thermionic diodes may also have one or two ancillary terminals for a heater. And while that sounds a bit esoteric, theyre actually among the handiest components ever to cross an engineers bench. Diodes have two active electrodes between which the signal of interest may flow, and most are used for their unidirectional electric current property. Most diodes are made with semiconductor materials such as silicon, germa. Diodes exclusively block current in the reverse direction whereas the reverse voltage is within a restricted vary and if not reverse barrier breaks and conjointly the. If a p and n region are heavily doped then the breakdown voltage can be reduced. Browse digikeys inventory of power zener diodeszener single.
Power is calculated by multiplying current by voltage pie, so we can calculate power dissipations for both the resistor and the zener diode quite easily. Diode schematic symbol and actual picture of a common 1n914 diode the black stripe in the picture is the cathode. As a result zener diode circuits are often used in power supplies when regulated outputs are needed. Apr 11, 2020 ppt zener diodes electrical engineering ee notes edurev is made by best teachers of electrical engineering ee. Terry sturtevant electronics zener diodes and photodiodes.
A subsurface zener diode, also called buried zener, is a device similar to the surface zener, but with the avalanche region located deeper in the structure, typically several micrometers below the oxide. This will be a brief note on different types of diodes with basic functionality and its circuit symbol. An ordinary diode operated in this region will usually be destroyed due to excessive current. Zener diode applications chapter 3 overview zener diodes zener characteristics zener diodes diode types rectifier zener lower vz due to more. In the nonconduction region, ideally all of the voltage is across the diode, the current is 0a, the reverse resistance r r is defined as r r v r i r, the diode acts like open. Avalanche diode construction, working and its applications. Types of diodes small signal, led, schottky, zener. Ppt zener diode applications powerpoint presentation free. Ppt zener diode powerpoint presentation free to download id. Diodes and diode applications topics covered in this ppt semiconductor materials the pn junction diode voltampere characteristic curve diode app.
Ppt zener diode applications powerpoint presentation. The zener diode or voltage reference diode is an electronic component that provides a stable and defined voltage. Dec 19, 2017 apr 11, 2020 ppt zener diodes electrical engineering ee notes edurev is made by best teachers of electrical engineering ee. Zener diode a zener diode is designed to operate in the. Find powerpoint presentations and slides using the power of, find free presentations research about zener presentation ppt. This document is highly rated by electrical engineering ee students and has been viewed 457 times. A zener diode is a diode that breaks down at a specific voltage when it is reverse biased. Zener diode characteristic apparatus electronics equipmentzener diode characteristic apparatus with build in stabilized power supply. Basic diode electronics introduction to diodes the pn junction the pn junction is a homojunction between a ptype and an ntype semiconductor. Zener diodes are like ordinary pn junction diode except that it is properly doped so as to have a sharp breakdown voltage. Recipe for solving diode circuits state of diode is unknown before solving the circuit 1. By passing a small current through the diode from a voltage source, via a suitable current limiting resistor r s, the zener diode will conduct sufficient current to maintain a voltage drop of vout. Ppt zener diodes electrical engineering ee notes edurev.
Use the diode equation for that state to solve the circuit equations and find i d and v d 3. Power supply, output and meters connections are brought out on the panel. Clamping basic diode operation forward bias terry sturtevant electronics zener diodes and photodiodes. That means when the voltage is increased the current through it decreases. Semiconductor diode questions and answers pdf free download mcqs interview objective type questions for eee ece electronics students semiconductor diode skip to content engineering interview questions,mcqs,objective questions,class notes,seminor topics,lab viva pdf free download. This voltage is generally avoided in standard diodes, but. Feb 09, 2015 construction of zener zener diodes are designed to operate in reverse breakdown. This needs to be taken into account if the circuit and equipment in which the zener diode is to be used is subject to temperature change. A lightemitting diode led is a diode that emits a certain color light when forwardbiased.
They can also be used in other circuits apart from just providing a voltage reference. Diodes zener diodes photodiodes optical isolation basic diode operation application. In this case the electrons and holes are swept across the junction an large current flow through it. It is acting as normal diode while forward biasing. Zener diode and regulators zener diodes are used to maintain a fixed voltage. Zener diode voltage regulator ppt video online download. Ppt zener diode powerpoint presentation free to download. The voltage across the diode is fairly constant 26mv for 25 c. This article discusses about a brief information about the construction and working of an avalanche diode. A free powerpoint ppt presentation displayed as a flash slide show on id. View and download powerpoint presentations on zener presentation ppt. Power zener diodes sanken zener single online catalog. The zener diode working principles and its various applications. Zener diode temperature characteristic it can be seen in the example given that there is a noticeable difference between the specification for the zener diode reverse voltage at 0c and 50c.
In our previous articles, we explain in detail about diodes, pn junction diode, semiconductors etc. I finished my electronics homework but im not so 100% sure if i did it right. Zener effect dominates at reverse voltages less than 5 volt whereas avalanche effect dominates above 5 v. Zener diodes diodes that can be made to conduct backwards. Ppt zener diode powerpoint presentation, free download id. The reverse breakdown of a pn junction may occur either due to zener effect or avalanche effect. Zener diode is a pn junction diode specially designed to operate in the reverse biased mode. Esaki diodes was named after leo esaki, who in 1973 received the nobel. Respectively a zener voltage regulator with fixed power supply and load, and a zener voltage regulated with fixed power supply and variable load. The problems that i have doubts about are number 5 and 6.
Zener diode voltage regulators 2 the forward bias region of a zener diode is identical to that of a regular diode. Zener diode forward bias when a zener diode is forward biased, it operates as a normal diode. Workable on 230 volts, ac fitted with zener diode 8. Zener diode working, characteristics and application as. A simple zener diode voltage regulator in the voltage regulator the zener diode operates in the breakdown region, which ensures approximately constant voltage across it. Zener diode is nothing but a single diode connected in a reverse bias mode and zener diode can be connected in reverse bias positive in a circuit as shown as picture. Diodes zener diodes photodiodes optical isolation application. Typical diodes have a very high reverse breakdown voltage, the voltage at which the diode begins to conduct in the reverse direction. The avalanche break down occurs in both rectifier and zener diodes at a sufficiently high reverse voltage. 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. In the reverse bias condition the zener diode is an open circuit and there is only a small leakage current in the microampere range. Diode a diode is a specialized electronic component with two electrode called the anode and the cathode. As the breakdown voltage is approached the current will begin to avalanche. Zener diode free download as powerpoint presentation.
Zener diodes a major application for zener diodes is a type of voltage regulator for providing stable reference voltages for use in power supplies, voltmeters, and other instruments. Zener diode voltages as well as producing a single stabilised voltage output, zener diodes can also be connected together in series along with normal silicon signal diodes to produce a variety of different reference voltage output values the values of the individual zener diodes can be chosen to suit the application while the silicon. The zener diode exhibits a constant voltage drop when sufficiently reversedbiased. Zener diode breakdown diode ppt video online download. These include small signal diodes, zener diodes, light emitting diodes, schottky diodes, tunnel diodes, avalanche diodes, etc. It acts as a diode, which can serve in electronics as a rectifier, logic gate, voltage regulator zener diode. Powerpoint slide on light emitting diode leds compiled by c. The circuit symbol of zener diode is as shown in the figure. The breakdown voltage of zener diodes will be constant for a wide range. Zener diode voltage regulators 6 for step 3 we calculate the maximum power dissipation of the zener diode. Power above 500 mw, zener diodes, diodes and rectifiers manufactured by vishay, a global leader for semiconductors and passive electronic components. Diode clamper zener has bad leakage dont forget about failure mode. View and download powerpoint presentations on zener diode as voltage regulator ppt. Zener diodes are used in circuits to maintain a fixed voltage across a load.
Zener diodes can be used to produce a stabilised voltage output with low ripple under varying load current conditions. This effect, called zener breakdown, occurs at a precisely defined voltage, allowing the diode to be used as. In this article, we are going to explain zener diode and its applications in detail. Zener diode is a reversebiased heavilydoped pn junction diode which operates in the breakdown region. Zener diode characteristic apparatus electronics equipment zener diode characteristic apparatus with build in stabilized power supply. Abidur rahman 1509056 electronics and communication engineering pritom mojumder 1509053. This property allows the use of the zener diode as a simple. Zener diode properties the zener diode is a unique device which exploits a property of diodes that is generally avoided in standard diode applications.
A zener diode is heavily doped to reduce the reverse breakdown voltage. Dec 11, 2017 diode seminar ppt and pdf report download. Hence comparing the schematic symbol to the pn junction in figure 4, we see the anode is the ptype semiconductor and the cathode is the ntype semiconductor. Features, specifications, alternative product, product training modules, and datasheets are all available.
Write down all circuit equations and simplify as much as possible 2. Zener diodes if we connect a diode and resistor in series with a dc voltage source so that the diode is forwardbiased, the voltage drop across the diode will remain fairly constant over a wide range of power supply voltages as in figure below a. Zener diode is a special kind of diode which permits the flow of current in the forward direction as well as in reverse direction when the voltage is above a certain voltage known as breakdown or zener voltage. Zener diodes are normal pn junction diodes operating in a reverse biased condition. Zener diode applications chapter 3 overview zener diodes zener characteristics zener diodes diode types rectifier zener lower vz due to more heavily. Zener breakdown occurs in a zener diode at low reverse voltages. A zener diode is like a normal silicon diode, where a forward biased diode will pass current with a 1 volt drop. Diodes and diode circuits tlt8016 basic analog circuits 20052006 11 3. Tunnel diodes esaki diode tunnel diode is the pn junction device that exhibits negative resistance. Basic electronics notes on vi characteristics of zener. A zener diode is a special diode that has been optimized for operation in the breakdown region. Zener diode working with circuit diagram and applications.
Power above 500 mw zener diodes diodes and rectifiers. A diode is also a tool that exclusively permits unidirectional flow of current if the diode is operated at a particular voltage level. Find powerpoint presentations and slides using the power of, find free presentations research about zener diode as voltage regulator ppt. Ee40 lec 18ee40 lec 18 diode circuitsdiode circuits. Diodes and diode applications electronics ppt web4study. P517617 lec5, p1 diodes and transistors diodes what do we use diodes for. The zener diode is a form of semiconductor diode that is widely used in electronics circuits as a voltage reference. A zener diode is a type of diode that allows current to flow in the conventional manner from its anode to its cathode i. When the doping is heavy, even the reverse voltage is low, the electric field at barrier will be so strong thus the electrons in the covalent bonds can break away from the bonds. The zener diode is a silicon pn junction device, which differs from a semiconductor diode, in the sense, that it is operated in the reverse breakdown region. In this presentation, we will see how the zener diode maintains a nearly constant dc.1435 225 1408 245 307 1246 85 658 857 1475 172 920 735 9 29 1473 135 1406 492 341 1285 901 520 1144 1329 1294 647 924 1339 111 955 1046 158 181 1491