Series Zener Diodes

Thread Starter

Joster

Joined Jun 12, 2013
95
Hi All,

Are two 15V Zener diodes in series basically the same as a 30V zener???
 

crutschow

Joined Mar 14, 2008
23,306
The are the same except for a possible difference in their combined impedances at breakdown (the zener impedance). You have to look at the respective data sheets to see.
 

to3metalcan

Joined Jul 20, 2014
259
The other way they're different is if the circuit also makes use of their .7V forward breakdown...obviously two diodes is going to give you two voltage drops instead of one!
 

MikeML

Joined Oct 2, 2009
5,444
The other way they're different is if the circuit also makes use of their .7V forward breakdown...obviously two diodes is going to give you two voltage drops instead of one!
So put a 1n914 or 1n400x in inverse parallel with the two series Zeners...:D
 

to3metalcan

Joined Jul 20, 2014
259
Mike - heh, there may or may not be a few high-powered bass amps with exactly that arrangement lumped into them and doused in hot glue floating around the East Bay...
 

ErnieM

Joined Apr 24, 2011
7,992
Two (equal) zeners in series also have twice the dissipation as one.
 
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