[otw_is sidebar=otw-sidebar-1]symbol of diode
I hope you all are fine; this is the third article in the series in which I am discussing the discrete electronic components employed in the electronic circuits. In this article I will discuss about the diode which is an electronic component employed in a lot of different kinds of circuits.

Introduction to Diode


After reading this article the reader will be able to learn the construction of diode, working of the diode, depletion region of the diode and most importantly the applications of the diode. So sit back, keep reading and enjoy learning.



What is a Diode  :


The diode is an electronic component which allows the current to flow in one direction and at the same time inhibits the flow of current in opposite direction. The term diode is composition of two terms “di” which means “two” and “ode” which means “two”. The diode is a two terminal passive electronic component, one terminal of the diode is called the anode and another terminal is called the cathode, due to this reason the term diode is used for this electronic component.

Symbol of Diode:

The schematic symbol of diode is as shown in the following image:

symbol of diode,what is diode

As shown in the above image that the symbol of the diode is essentially the arrow sign with the bar at its front end. The arrow sign points out the direction in which the diode allows conduction.

 [otw_is sidebar=otw-sidebar-3]

PN Junction:

PN junction is an important entity and has applications in many electronic components. PN junction is formed when one side of the silicon is doped with an acceptor element and the other side is doped with donor element. Diodes are optimized for different applications the most simple and basic diode is called the PN diode and this diode is essentially the PN junction. Some of the common types of diodes are:

  • Zener diode.
  • Avalanche diode.
  • TVS (Transient Voltage Suppression) diode.
  • Photodiode etc.

The basic construction of the simple PN diode is as shown in the following figure:

PN Junction,N-Region ,P-Region

P-Region and N-Region:

As shown in the above image N-Region of the diode also called the Cathode has electrons as majority charge carriers and the P-Region of the diode also called the Anode has the Hole as the majority charge carriers.






Depletion Region:

Before going into the discussion on the biasing of the diode let us first consider an important concept used in the diode. When a PN junction is formed it is essentially unstable the electrons from the N-region escapes the junction and enter into the P-Region similarly the holes from the P-Region escapes and enter into the N-Region. When either charge carrier leaves its region it leaves the ion behind it and which accumulates and form the electric field. This electric field inhibits the charge carriers to further move across and the region of the electric field deprives of any type of charge. This region is called the depletion region as it is depleted of any type of charge carrier. The visualization of the Depletion Region in the diode is as shown in the following figure:


Depletion Region


Applications of the Diode:

  • The diodes are used in AC to DC converters.
  • The diodes are used polarity protection.
  • The diodes are used in amplifiers for bootstrapping.
  • The diodes are used in voltage reference circuits.
  • The diodes are used as freewheeling diode in order to protect circuits from voltage spikes.

I hope this article would be helpful for you, that is all for now, in this article I have discussed the basics of diode, working, construction and depletion region of the diode. In the next article I will come up with more interesting topics in engineering. Till then stay connected, keep reading and enjoy learning.