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zener and pn diode

bhuvanesh

Aug 29, 2013
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The transfer characteristics of zener and pn diode looks same in reverse bias, i have asked few why in many rectifier circuits zener is used.i got answer like, it wont burn up in high reverse current like pn diode . why zener is special than pn diode.
 

Harald Kapp

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Nov 17, 2011
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why in many rectifier circuits zener is used.i got answer like, it wont burn up in high reverse current like pn diode
add 1) As far as I know zeners are not used in many rectifier circuits.
add 2) A rectifier is designed to have no reverse current, therefore using zener diodes is contra-productive.
add 3) a zener diode is a pn diode with a defined reverse breakdown voltage, that's what it makes special. When it comes to reverse breakdown, a standard pn diode has a comparatively high and not well defined breakdown voltage. Once a breakdown happens, the power dissipation will be high (P=V*I), possibly higher than that of a zener diode with a lower breakdown voltage. Did I say that breakdown should never occur in a rectifier?

Here's a discussion on this topic with all the arguments.
 
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bhuvanesh

Aug 29, 2013
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A rectifier is designs to have no reverse current, therefore using zener diodes is contra-productive.
At breakdown voltage its supplying constant voltage with increase in reverse current,its apparent from transfer characteristics ,Then how do you say that zener dont have any reverse current .
 
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