The heart of the zener voltagereference is shown in the. Zener diode working with circuit diagram and applications. This manual was prepared to acquaint the engineer, the equipment. The vi characteristics or voltagecurrent characteristics of the pn junction diode is shown in the below figure. Pdf v i characteristics of diode through computer researchgate. The symbol of zener diode is similar to the normal pn junction diode, but with bend edges on the vertical bar.
A zener diode is constructed for operation in the reverse breakdown region. For zener diodes, silicon is preferred to ge because of its high. Here you will learn, how the zener diode is used in reverse biasing. This voltage is generally avoided in standard diodes, but zener diodes are designed and manufactured to have a very specific reverse breakdown voltage. A pnjunction diode is formed when a ptype semiconductor is fused to an ntype semiconductor creating a potential barrier voltage across the diode junction the effect described in the previous. Zener diode as voltage regulator tutorial electronicstutorials.
Forward biasing will cause a large i f with a rather small value of v. 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. Zener diodes are heavily doped than ordinary diodes. The forward characteristics of a zener diode is shown in figure. Vi characteristics of zener diode vi characteristics of. This post includes explanation of operation of zener diode and vi characteristics of zener diode. Pdf the various attempts have been made to simulate the experiments using computer.
A diode allow electric current to pass in forward direction. In some cases, excess current flows through a circuit and damage the multimeter. 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. The circuit symbol of zener diode is as shown in the figure. The vi characteristics of a zener diode is shown in the below figure. Electronics tutorial about the zener diode and how the zener diode can be used. Electrons diffuse across the junction and combine with majority holes.
This manual was prepared to acquaint the engineer, the. The breakdown voltage of a zener diode can be set by controlling the doping level. Determine several diode parameters, investigate iv characteristics of diodes and zener diodes when forward or reverse bias is applied, and understand the behavior of simple diode circuits. In reverse bias, a negligible constant current flow through the zener diode but the current becomes abruptly large at certain voltage. Basic electronics notes on vi characteristics of zener diode in pdf. The reason a zener diode has a maximum current is because the diode has a power rating, p zm which cant be exceeded.
The zener regulator is composed of resistor r1 and zener diode cr1 the resistor characteristics are. The power, pzm is normally a given rating with the zener diode. Diode is reverse biased when cathode is made positive with respect to anode. 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. Pdf explain a little about the zener diode sina taherinasab. When forward biased voltage is applied to the zener diode, it works like a normal diode.
The characteristics of a regular junction diode will show that it is designed primarily for operation in the forward direction. The resultant iv characteristics equation of a junction diode is given by. The simplest semiconductor device is a pnjunction diode. Pdf electronic circuits in certain space missions are exposed to very low temperatures. The relationship is obtained by applying kvl and it is vs vg r im. The horizontal line in the below figure represents the. The zener diode is a particular type of diode that solves this problem. Zener diode zener diode operates in reverse bias rb at the zener voltage v z. Normally it is called the vi characteristics of a general p n junction diode. This video lecture explains the vi characteristics of the zener diode. The vi characteristic of zener diode indicates that characteristic of zener diode in forward bias is same as pn junction diode. This paper shows the vi characteristics of diode through pc that records the different readings of voltage across diode and current.
Basic electronics notes on vi characteristics of zener. In forward bias zener works as an ordinary diode but when. V z0 is the voltage at which the straightline approximation of the iv characteristic intersects the horizontal axis. Due to its doping characteristics, the zener diode is made to use at high breakdown voltage. Typically there is also a minimum current required for the operation of the. But for simplicity, both types are called zener diodes. Thus the load voltage remains at constant by altering the current flow through the zener diode.
Zener diode, vi characteristics, working, and applications. Electrical characteristics tamb 25 c, unless otherwise specified part number zener voltage range 1 test current reverse leakage dynamic resistance f 1 khz surge current 3 regulator 2. Analysis and measurement of a zener diode voltagereference. A semiconductor diode is the most common type diode, which is a piece of semiconductor material with a pn junction connected to two terminals. Hbd854 zener theory and design considerations handbook. Characteristics of a zener diode the above diagram shows the vi characteristics of. The vi characteristics of a zener diode is shown in the below. I zener do you see any relationship between source voltage and zener diode current. When reverse biased, a small reverse current known as leakage current flows. But zener breakdown voltage occurs when the reverse bias voltage is greater than a predetermined voltage. Zener diode is significant to use in breakdown region. Thus, zener diodes protect it from damage by providing voltage regulation. Every zener diode has particular zener voltage knee voltages in that they can regulate voltage.
Pdf performance of shunt voltage regulators based on zener. The vi characteristics of a zener diode can be divided into two parts i forward characteristics ii reverse characteristics. From the iv characteristics curve above, we can see that the zener diode has a. A zener diode is a type of diode that allows current to flow in the conventional manner from its anode to its cathode i.