In on state, the voltage across zener diode remains constant until the voltage across it deops less than vz. Use the diode equation for that state to solve the circuit equations and find i d and v d 3. Apr 30, 2020 ppt zener diodes electrical engineering ee notes edurev is made by best teachers of electrical engineering ee. The basic purpose of a power supply is to provide one or more fixed voltages to the working circuit, with sufficient current handling capacity to maintain the operating conditions of the circuit. Write down all circuit equations and simplify as much as possible 2. 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. Hbd854 zener theory and design considerations handbook. Ppt diodes powerpoint presentation free to download id. So it was all about seminar on diode with ppt and pdf report, if you liked it then please share this seminar with your friends. This property of zener diode makes its use as a voltage regulator. Ppt special purpose diodes powerpoint presentation free. From the iv characteristics curve above, we can see that the zener diode has a region in its reverse bias characteristics of almost a constant negative voltage regardless of the value of the current flowing through the diode. Diode circuits tutorial pdf 25p this note covers the following topics.
This document is highly rated by electrical engineering ee students and has been viewed 457 times. May 10, 2016 career point cares zener diodes are a special kind of diode which permits current to flow in the forward direction. Dec 11, 2017 diode seminar ppt and pdf report download. A zener diode is a type of diode that allows current to flow in the conventional manner from its anode to its cathode i. Normal diodes will also break down with a reverse voltage but the voltage and sharpness of the knee are not as well defined as for a zener diode. Ppt diode powerpoint presentation free to download id. Diode a diode is a specialized electronic component with two electrode called the anode and the cathode.
In a dc circuit, zener diode can be used as a voltage regulator or to provide voltage reference. Zener diode forward bias when a zener diode is forward biased, it operates as a normal diode. A zener diode is heavily doped to reduce the reverse breakdown voltage. Zener diode has the property of behaving like a dc battery in on state i.
This breakdown voltage is known as the zener voltage. The zener diode provides the reference voltage, but a series resistor must be in place to limit the current into the diode otherwise a large amount of current would flow through it and it could be destroyed. The main use of zener diode lies in the fact that the voltage across a zener diode remains constant for a larger change in current. Zener voltage is defined as the voltage at which the zener diode breaks down. A diode can be defined as the fundamental electronic component that allows the flow of electricity in one direction only.
Most diodes are made with semiconductor materials such as silicon, germa. Ppt zener diode applications powerpoint presentation, free. This type of break down occurs normally for a highly doped diode with low breakdown voltage and a larger electric field. Zener diode symbol zener diode circuit zener diode vi characteristics zener diode working zener diode applications faqs. Recipe for solving diode circuits state of diode is unknown before solving the circuit 1. Important features zener diodes have a highly doped pn junction. In this case the electrons and holes are swept across the junction an large current flow through it. Zener diode definition a zener diode is a type of diode that permits current to flow in the forward direction like a normal diode, but also in the reverse direction if the voltage is larger than the breakdown voltage known as zener knee voltage or zener voltage. Normal diodes will also break down with a reverse voltage but the voltage. Leds are semiconductor diodes, electronic devices that permit current to flow in only one direction.
The adobe flash plugin is needed to view this content. A diode is a twoterminal electronic component that conducts primarily in one direction. View and download powerpoint presentations on zener diode ppt. 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. Top list of types of diodes and their applications zener, light emitting. A zener diode is a special diode that has been optimized for operation in the breakdown region. Ppt zener diode powerpoint presentation, free download id. Find powerpoint presentations and slides using the power of, find free presentations research about zener diode ppt.
Scribd is the worlds largest social reading and publishing site. An imagelink below is provided as is to download presentation. Ppt zener diode powerpoint presentation free to download id. This property allows the use of the zener diode as a simple. The color of light emitted by an led is determined by the type of material used in doping. Find powerpoint presentations and slides using the power of, find free presentations research about tunnel diodes ppt. Ppt zener diode applications powerpoint presentation free. In optical fiber and free space optic communications. Feb 09, 2015 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 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. The value of resistor calculated to give required value of current for supply. A free powerpoint ppt presentation displayed as a flash slide show on id. Remote controls, such as for tvs and vcrs, often use infrared leds. Power above 500 mw zener diodes diodes and rectifiers.
Ppt zener diodes electrical engineering ee notes edurev. Oct 27, 2018 displaying powerpoint presentation on the zener diode w3oi available to view or download. Zener diode and regulators zener diodes are used to maintain a fixed voltage. To draw the reverse characteristic curve of a zener diode and to find its reverse breakdown voltage. Ppt diodes powerpoint presentation free to download. 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. Zener diode circuit the most basic zener diode circuit consist of a single zener diode and a resister. Dec 19, 2017 apr 30, 2020 ppt zener diodes electrical engineering ee notes edurev is made by best teachers of electrical engineering ee. A diode is also a tool that exclusively permits unidirectional flow of current if the diode is operated at a particular voltage level. The zener diode is used in its reverse bias or reverse breakdown mode, i. Basics currentvoltage characteristic of a zener diode with a breakdown voltage of.
In the forward bias direction, the zener diode behaves like an ordinary silicon diode. 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. Diode schematic symbol and actual picture of a common 1n914 diode the black stripe in the picture is the cathode. A lightemitting diode led is a diode that emits a certain color light when forwardbiased. View and download powerpoint presentations on tunnel diodes ppt. 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 diode will always drop about 0.
The zener diode exhibits a constant voltage drop when sufficiently reversedbiased. How to control the breakdown voltage of zener diode. Zener diode applications chapter 3 overview zener diodes zener characteristics zener diodes diode types rectifier zener lower vz due to more heavily. Introduction the zener diode is a silicon pn junction devices that differs from rectifier diodes because it is designed for operation in the reversebreakdown region. The circuit schematic symbol of a diode is shown in figure 5. The zener diode working principles and its various applications. Zener diode breakdown diode ppt video online download. Ppt zener diode powerpoint presentation free to download. Zenerdiode voltageregulator circuits a voltage regulator circuit provides a nearly constant voltage to a load from a variable source. Outlines introduction of zener diode construction of zener diode working of zener diode application of zener diode numerical of zener diode 3. The diode is formed by bringing two slightly different materials together to form a pnjunction in a pn junction, the p side contains excess positive charge indicating the absence of electrons while the n side holes, contains excess negative charge electrons a simplified pn. 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.
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. Zener diode free download as powerpoint presentation. Izt usually is at the quarter power point, and izk is an. It is different from others diodes zener diodes will also allow current to flow in the reverse direction when the voltage is above a certain value. The active portion of a zener diode is a semiconductor pn junction.
Zener diode as a voltage regulator linkedin slideshare. An ordinary diode operated in this region will usually be destroyed due to excessive current. Ppt zener diode applications powerpoint presentation. 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. Diodes and diode applications electronics ppt web4study.
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