Question

What is knee voltage of PN junction?

Answer 1

1. In the forward characteristics of a diode once the voltage is applied then the junction starts increasing rapidly. It is known as knee voltage and an alternate name of this is cut in voltage.
2. The PN junction diode VI characteristics are simply a curve between the flow of current in the diode and the applied voltage across the two terminals of the diode.
3. The characteristics of diode separated into two divisions like forwarding characteristics and reverse characteristics.
4. The forward bias connection can be done by connecting p junction to the positive terminal and N junction to a negative terminal of the battery. In this arrangement, the majority charge carriers are holes & minority charge carriers are electrons.
   
5. When the PN junction diode is connected in forwarding bias using a battery, where the P junction is connected to a +ve terminal of the battery & the N junction is connected to the –ve terminal of the battery. This arrangement is called forward biasing of a diode. In this kind of arrangement, the diode works as a short circuit due to its less forward resistance within the range of ohms. It means the flow of current is very easy in this bias.
6. In the above characteristics of a diode, when the voltage across the diode increases then the current will be increased. If we notice in the graph, the diode current is extremely small up to a set point. The voltage is cross toward the barrier potential, the diode current raises quickly and diode performs greatly.
7. This barrier voltage at which the flow of current will increase is known as knee voltage.