CLASSIFICATION OF POWER DIODES:

All Power diodes are classified on the basis of reverse recovery time. Reverse recovery time means time taken to come to off state even after it is turned off. This is because of the minority charge carriers in the diode. Normally during the forward bias condition the holes and electrons move to either side after crossing the depletion region and then conduction takes places. Then some of the minority charge carriers (i.e., electrons) are trapped in the both regions and also in depletion region also. During off state even though we off the diode due to the minority charge carrier’s conduction takes place for some time. This time is called reverse recovery time. These are power diodes which are used for general purposes. Reverse recovery time is (few 10’s to micro seconds). And these are of low frequency. Another one is FAST RECOVERY DIODES in which reverse recovery time is about (30-500 nano sec). Last one is SCHOTKY DIODE in which reverse recovery time is about (< 30 nano sec). In this there is no minority charge carriers flow in reverse biased condition.