👉 Definition of Diode : The electronic device which has two (die) terminals (nodes) is called diode . A seprate piece of P- type and N - type semiconductor material has vary limited use.
⭐ However , when they are joined together , such that the crystal structure remains continuous at the boundary , a PN - junction is grown out of a Crystal . So , a semiconductor diode is also known as a CRYSTAL DIODE .
⭐ Here, a joining of P -type and N -type semiconductor is not mechanically . A junction semiconductor diode is made by taking a single piece of germinum or silicone and adding a donor impurity in one region and an accptor impurity to another region .
⭐ So, we get a single crystal with an N -section and a P -section . The point where two sections meet is called the junction . The schematic symbol of diode is shown figure.
⭐ Sometimes Anode is denoted arrow Head or blue dot while cathode is mentioned with bar or red dot. The Arrowhead in the symbol indicates the direction of conventional current flow when the diode is forward biased.
⭐ A diode is a two terminal device. The p side of the diode is called anode and N side of the diode is called cathode . When a DC voltage is appiled to the diode , the diode is said to be biased. The diode can be biased either forward or reverse . So, when diode is connected in a circuit , it is necessary to know whether diode is forward biased or reverse biased. For this , there I an easy rule as stated under .
⭐ If the external circuit is typing to push the conventional current in the direction of arrow , the diode is forward biased . On the other hand , if the conventional current is trying to flow opposite to Arrowhead , the diode is reversing biased.
Fig : various types of DIODE
