6.2 THE DIODE AS A SWITCH

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.

6.2.1 Diode Characteristics

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:

ch6-eq1

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 ...

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