The Zener Diodes is a special type of diodes that can used as a Voltage regulator with help of few components. So in this Article i’m explaining about the details of how Zener diode use as a voltage regulator and and its working.
First of all we need to know that what is diodes, zener diodes and how it is working. This is very important to know before going to the Main topic. So more understanding i’m explaining with diodes. What are diodes? How these diodes working in an DC current or AC current.
What is diode in electronics
Diode is an electronic component that will allows the passage of current in only one direction. The most common diode uses a p-n junction. In an another word the p-n junction diodes is one of the simple semiconductor device that will consuct the current trough the p-n juctions.
The p-n juction diodes are using as rectifiers and reverse voltage blocker in numerous electronic circuits. Why the p-n junction is also called as a juction diode? The p-n junction is allowing the large current flow through the forward bias and it will be highly resistance to the reverse bias. so their is a little complication in understanding.
Don’t worry using an image representation i can clarify the doubt’s about the p-n junction, Reverse bias and also the forward bias. From the name it self you can understand the reverse bias and forward bias term. lets look the below image to understand the terms in easy way.
Pn junction diode
If we are making the electrical connections in both ends of N-type and P-type material ( Because of the diode build with p and n type semiconductor material ). The P region connected to the Battery positive terminal, and the N junction connected to the battery negative terminal.
While this connection the free electrons able to crossing the depletion region from one side to other side. This behaviour of the pn junction with depletion layer as potential barrier produces an assymetric current conducting two terminal elewctronic component is Known as PN junction.
So with the help of image you can understand now. what about the forward bias and reverse bias, zero bias. now it is the time to explain more deep about the bias of diodes.
Zero bias
In zero bias condition means their is no external voltage potential applying in the PN junctions of the diode. so it is clear that the potential difference between the two ends of the diode is zero then it is called as the zero bias condition of a diode.
Reverse bias
The reverse bias, from the name reverse is representing that the reverse polarity connection of the diode. Yes, the potential difference is applied to the diode in reverse directions. the positive terminal of the battery is connecting to the N junction of the diode and The negative connection of the battery will connecting to the P junction of the diode.
So their is a big depletion layer is their in between the pn juction. the electrons will not passing through this depletion layer so their is no current passage through the diode is occurs.
Forward bias
From the name forward bias it is clear that the connections will be the in forwarded type. Means that the P juction is connecting to the positive terminal of the battery and the N juction is connecting to the negative terminal of the battery. the working is already discussed above paragraph so i’m not explaining more about the forward biasing.
For the above explanations about diode and its working reverse biasing, forwrd biasing is clear now i understand that you know about how a normal pn juction diodes are working it various electronic equipments. now we are going to the zener diode section.
Discussing about zener diode workings and also about zener voltage regulator circuit diagrams. A diode can regulate the input voltage ? it can deliver a constant potential diffrence?
What are zener diode
The zener diode is also a tiny semiconductor diode. which will conduct the current through it but with some conditions are their. The normal diodes are working in forward bias condition but the zener diodes will works in the reverse bias with a rated critical potential difference.
The zener diodes are not allow the current flow to the anode terminal to the cathode, in the reverse bias reaching the rated zener voltage. for example the zener diodes are available in the market with 3,3v, 5.1v, 6.2v, 10v, 11v etc. these are the turn on voltage of the zener diode.
Zener diode explanation
The zener diode is also known as reverse direction diode or breakdown diode. The diode is a heavily doped semiconductor. This electronic component is designed for working in reverse bias condition with special rated voltage.
Why is zener diode is use as voltage regulator
The zener diodes is using as voltage regulator because of the voltage drop across the diode is constant. The supply voltage need to high, above the zener diode voltage the diode start to conduct. The zener diode connected any device in parallel the voltage output will be constant.
What is the zener voltage of a zener diode
The brakdown voltage is the special characteristic of the zener diode. So every single zener diode is rated its own breakdown voltage in their data-sheet. The zener diode connecting in the circuit and in that time a constant voltage is developing in the circuit this is known as Zener Voltage.
If the voltage exceeds and the point of zener conduct the current in that point is known as the breakdown voltage of that zener diode.
Application of Zener diode
The zener diode using as a voltage regulator. The main thing is the voltage drop in the diode is constant. so we can implement this zener diodes in op-amp volt comparing the voltage ranges in many situation.
Also we can implement in led circuits to protect the high input voltage spikes. The diode connecting parallel with any components will get the same voltage range ( constant potential difference ).
