Basic Definitions

Basic Definitions

1.Knee voltage or Cut-in Voltage.
It is the forward voltage at which the diode starts conducting.

2. Breakdown voltage
It is the reverse voltage at which the diode (p-n junction) breaks down with sudden rise in reverse current.

3. Peak-inverse voltage (PIV)
It is the max. reverse voltage that can be applied to a p-n junction without causing damage to the junction.

If the reverse voltage across the junction exceeds its peak-inverse voltage, then the junction exceeds its Peak-inverse voltage, then the junction gets destroyed because of excessive heat. In rectification, one thing to be kept in mind is that care should be taken that reverse voltage across the diode during –ve half cycle of a.c. doesnot exceed the peak-inverse voltage of the diode.

4. Maximum Forward current
It is the Max. instantaneous forward current that a p-n junction can conduct without damaging the junction. If the forward current is more than the specified rating then the junction gets destroyed due to over heating.

5.Maximum Power rating
It is the maximum power that can be dissipated at the junction without damaging it. The power dissipated across the junction is equal to the product of junction current and the voltage across the junction.