The breakdown potential, also called the zener potential i. The heart of the zener voltagereference is shown in the. The vi characteristic of zener diode indicates that characteristic of zener diode in forward bias is same as pn junction diode. Basic electronics notes on vi characteristics of zener. But for simplicity, both types are called zener diodes. The symbol of zener diode is similar to the normal pn junction diode, but with bend edges on the vertical bar. For zener diodes, silicon is preferred to ge because of its high temperature and current capability. In reverse bias, a negligible constant current flow through the zener diode but the current becomes abruptly large at certain voltage. The zener diode is a particular type of diode that solves this problem. The excess voltage required for reversing the direction of flow of current is termed as breakdown voltage or zener voltage. Zener diode connection characteristics of a zener diode. Lab report zener diod free download as powerpoint presentation. When the diode is connected in forward bias diode acts as a normal diode. Zener diode working with circuit diagram and applications.
The zener regulator is composed of resistor r1 and zener diode cr1 the resistor characteristics. Also, we describe how the zener diode is used as a voltage regulator, a clipping circuit and as a voltage reference. The above diagram shows the vi characteristics of the zener diode behavior. The limiting maximum power for a zener diode is given by p zv zi zmax and is a function of the design and construction of the diode.
Reverse biasing will generally not cause current conduction until higher values of reverse voltage are reached. Due to its doping characteristics, the zener diode is made to use at high breakdown voltage. Scribd is the worlds largest social reading and publishing site. Zener diodes are heavily doped than ordinary diodes. The breakdown voltage of a zener diode can be set by controlling the doping level. 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. When the reverse bias voltage is greater than a predetermined voltage then the zener breakdown voltage occurs.
In some cases, excess current flows through a circuit and damage the multimeter. Thus, zener diodes protect it from damage by providing voltage regulation. Let us learn about this exciting and unique kind of diode. It is fairly employed in many electrical and electronic tools and equipments.
This post includes explanation of operation of zener diode and vi characteristics of zener diode. In zener diode, electric current flows from both anode to cathode and cathode to anode. In this lesson we define the zener diode and describe its characteristics. The major role of a zener diode is to function as a voltage regulator. Analysis and measurement of a zener diode voltagereference. Zener diode is significant to use in breakdown region. Forward biasing will cause a large i f with a rather small value of v f. The characteristics of a regular junction diode will show that it is designed primarily for operation in the forward direction. The zener diode varies in a wider range based on its mounting location.
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