ZENER DIODE

A Zener diode is specially designed so as to have a  reduced breakdown voltage, the so-called Zener voltage. A Zener diode contains doped p-n junction allowing electrons to Channel from the valence band of the p-type material to the conduction band of the n-type material

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The basic parameters of a zener diode are:

(a) The zener voltage must be precised. The most common range of zener voltage is 3.3 volts to 75 volts.
 
(b) Most popular tolerances are 5% and 10%, more precision tolerances as low as 0.05 % are available . A test current (Iz) must be specified with the voltage and tolerance.

(c) The power handling capability must be specified for the zener diode. Popular power ranges are: 1/4, 1/2, 1 , 5, 10, and 50 Watts