As we have gone through the first part of the article we know what is zener diode and what is the basic principle of operation. As stated above the basic principle behind the working of a zener diode lies in the cause of breakdown for a diode in reverse biased condition. 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 zener diode operates just like the normal diode when in the forwardbias mode, and has a turnon voltage of between 0. The zener diode is mostly used in the commercial and industrial applications. The zener voltage refers to the reverse breakdown voltage2. The symbol of zener diode is shown in the figure below. Zener diode voltage regulators 2 the forward bias region of a zener diode is identical to that of a regular diode. Z ener diode as the name suggests is a two terminal device with two terminals being anode p and cathode n.
Zener diodes vary in specifications such as nominal working voltage, power dissipation, maximum reverse current, and packaging. It is acting as normal diode while forward biasing. Zener diode working, characteristics and application as. Zener diodes are normal pn junction diodes operating in a reversebiased condition. Diode input voltage, minority carrier concentration, diode current and diode voltage a. Free electrons with sufficient kinetic energy collide with stationary ions of the depletion layer and knock out more free electrons. Write down all circuit equations and simplify as much as possible 2. 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.
The zener diode can work as a voltage regulator if it is introduced in a circuit. Zenerdiode written method in practical file youtube. The basic diagram of zener diode as voltage regulator is given below. 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 zener diode is special type of diode mainly used in circuits like reference voltage. A zener diode is a silicon semiconductor device that permits current to flow in either a forward or reverse direction. Recipe for solving diode circuits state of diode is unknown before solving the circuit 1. A specific diodes vf depends on what semiconductor material its made out of. The zener diode working principles and its various applications. The zener diode is used in its reverse bias or reverse breakdown mode, i. Working of the zener diode is similar to a pn junction diode in forwarding biased condition, but the uniqueness lies in the. Zener diode operation and applications ece tutorials. 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. The relationship is obtained by applying kvl and it is vs vg r im. A zener diode is a type of diode that allows current to flow in the conventional manner from its.
With the switch up, the zener will limit vout to 4 volts. A diode can be defined as the fundamental electronic component that allows the flow of electricity in one direction only. The limiting maximum power for a zener diode is given by pzvzizmax and is a function of the design and construction. A zener diode allows current to flow from its anode to its cathode like a normal semiconductor diode, but it also permits current to flow in the reverse direction when its zener voltage is reached. Zener diode is a pn junction diode specially designed to operate in the reverse biased mode. Usually, the condition of the diode with basic pn as its junction during reverse bias is that there is no chance of conduction. Power is calculated by multiplying current by voltage pie, so we can calculate power dissipations for both the. Pdf explain a little about the zener diode sina taherinasab.
Typically, a silicon diode will have a vf around 0. A zener diode is a type of diode that allows current to flow in the conventional manner from its anode to its cathode i. It has a particular voltage known as break down voltage, at. Zener diode properties the zener diode is a unique device which exploits a property of diodes that is generally avoided in standard diode applications. When reverse voltage vr applied to the zener diode exceeds the break down. Pin configuration, anode and cathode electronic symbol zener diode symbol2. Minimum current required for the diode to break down5 ma and 10 ma. Basic diode electronics introduction to diodes the pn junction the pn junction is a homojunction between a ptype and an ntype semiconductor. 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. Zener diode as a voltage regulator zener diode is a silicon semiconductor with a pn junction that is specifically designed to work in the reverse biased condition. Zener diode as a voltage regulator working principles. The following are the main application of the zener diode.
Hbd854 zener theory and design considerations handbook. Application of zener diode as we have gone through the first part of the article we know what is zener diode and what is the basic principle of operation of 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. Many types of diode are used for a wide range of applications. D1n750 zener diode datasheet pdf united pdf comunication. Zener diode working with circuit diagram and applications. As we get into the why, we will do some measurements on a real zener diode. The zener diode working principles and its various. Maximum current at the rated zener voltage vz200 ua to 200 a.
Zener diode symbol zener diode circuit zener diode vi characteristics zener diode working zener diode applications faqs. Zener diodes cannot be tested individually with a multimeter. Zener diode made specially to operate in the reverse breakdown region. For high frequency applications rectifier power diode can not be used, this is due to the long reverse recovery time of. As we know if the voltage across the diode exceeds a certain value it would draw excessive current from the supply. Zener diode characteristics, working and applications. Types of diodes small signal, led, schottky, zener. It is that reverse bias voltage at the which junction breakdown completely and large current flows through the device at a constant potential reverse. Zener diode as voltage regulator tutorial electronicstutorials. The zener diode is a form of semiconductor diode that is widely used in electronics circuits as a voltage reference. It is because multimeters usually do not have enough input voltage to put the zener into breakdown region. These diodes are heavily doped in order to have narrow depletion region. In the reverse bias condition the zener diode is an open circuit and there is only a small leakage.
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