Semiconductor and Zener diodes can be used in switching applications. To understand the working of a two-terminal device as a switch, we need to consider its V–I characteristic and switching times.
A p-n junction diode can be used as a switch. When the diode is forward-biased, the switch is said to be in the ON state and when it is reverse-biased, the switch is in the OFF state. Figure 6.1 shows the V–I characteristic of a p–n junction diode.
The diode current is given by the relation:
where, V is the bias voltage, η = 1 or 2 depending on whether it is a Ge or Si diode and VT is the Volt-equivalent ...