After reading this post the reader will be able to learn about the basics of the Schottky diode, its construction, working and application. So sit back, keep reading and enjoy learning.
Introduction to Schottky diode:
Schottky diode also known as the hot carrier diode is a two terminal passive electronic component and a special purpose diode. Its forward and reverse biased characteristics are quite similar to that of the normal PN junction diode however its construction is different from that. The Schottky diode is a unipolar device that is only one type of charge carriers is involved in the operation of the diode. Schottky diode is the high speed device due to its specially designed junction and thus is employed in high speed applications. The threshold voltage of the Schottky diode in the forward biasing is smaller as compared to the normal PN junction diode and due to this this efficient in switching applications. The schematics symbol of the Schottky diode is as shown in the following image:
Construction of Schottky Diode:
As pointed earlier that the construction of the Schottky Diode is different from that of the normal PN junction diode. The Schottky diode employs the metal-semiconductor junction instead of the PN junction which is employed in normal PN diodes. A metal and a semiconductor combine to form a junction known as Schottky Barrier which has electrical characteristics quite different from the PN junction. The semiconductor used in Schottky diode is typically N-type and metals employed in the diode can be:
It is due to the metal-semiconductor junction which enables high speed response of the device.
Ohmic contact is an important concept in electronics. It is due to this which enables the metallic leads to be connected to the semiconductor devices such as in the diodes or transistor or any other electronic component. The Ohmic contact is also a metal-semiconductor junction when the N-region of the junction is highly doped the junction does not acts as the rectifier and becomes the Ohmic which enables the current flow in either direction just like the conductor.
The basic construction of the hot carrier diode is a shown in the following image:
Working of the Schottky Diode:
The basic construction of the diode is similar to the normal PN junction diode that is it allows the current to flow in one direction and opposes its flow in the other direction. The forward threshold voltage of the normal PN junction diode is almost 600-700millivolt whereas the Schottky diode has very low forward threshold voltage of about 150-450 millivolt. The comparison of Voltage –Current characteristic of the hot carrier diode and the normal PN junction diode is as shown in the following image:
Applications of the Schottky Diode:
Due to the fast response of the Schottky diode it finds application in high speed circuits. Some of the applications of the Schottky diode are:
- Schottky diode is used in AC to DC converter.
- Schottky is also employed in high current power supplies.
- Schottky diodes are used in mixers.
- Schottky diodes also find applications in radar systems.
- Schottky diodes are used in voltage clamper circuits.
What is Schottky Diode
I hope this article “Introduction to Schottky diode”would be helpful for. I have discussed basics of the Schottky diode in this article. That is all for now in the next article I will come up with more interesting engineering topics. Till then stay connected, keep reading and enjoy learning.