Maker Pro
Maker Pro

Zener Current = ?

TheLaw

Sep 27, 2010
119
Joined
Sep 27, 2010
Messages
119
Hi,

I'm trying to find the right Zener for a project. I know that Zeners stabilze the voltage at a set voltage...but what is the definition of Zener current?

I have choices of 20mA all the way up to 250mA. Is this the maximum current it can pass at its given Zener voltage? That's about the only possibility I can think of. So is higher better? Or is it application specific?

Thanks.
 

davenn

Moderator
Sep 5, 2009
14,254
Joined
Sep 5, 2009
Messages
14,254
Generally Zeners are voltage and Wattage rated ie...

5V6 and 1W 6V8 and 0.5W etc

so W / V = Amps of current that will be the max for that particular diode

Dave
 

TheLaw

Sep 27, 2010
119
Joined
Sep 27, 2010
Messages
119
So that's the max that it can pass...not max that it WILL pass...Just making sure. Don't think that's possible anyway.

Thanks.
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
Joined
Jan 21, 2010
Messages
25,510
Well, a zener can pass almost any current. At high currents the power dissipation will kill the device.

Some parameters are given at different currents because zeners are not perfect and the change in voltage for small changes in current will differ depending on the current. This results in a change in the apparent impedance of the device.

In some applications it is preferable to operate the zener at around 80% of its max current.
 
Top