# zener diode operating current

Started by February 28, 2012
```I want to use this 100V zener, and I'm trying to figure out how much
current it draws when it's turned on, on the datasheet I see

Vz "working voltage" is between 95V-105V with the condition Iz = 1 mA

does that mean that as long as I make sure the zener is capable of
getting at least 1mA that this will conduct when I go over 100V?

here's the zener I'm looking at

http://www.nxp.com/documents/data_sheet/BZX100A.pdf

thanks!
```
```panfilero wrote:
> I want to use this 100V zener, and I'm trying to figure out how much
> current it draws when it's turned on, on the datasheet I see
>
> Vz "working voltage" is between 95V-105V with the condition Iz = 1 mA
>
> does that mean that as long as I make sure the zener is capable of
> getting at least 1mA that this will conduct when I go over 100V?
>
> here's the zener I'm looking at
>
> http://www.nxp.com/documents/data_sheet/BZX100A.pdf
>
> thanks!

Yes.  It will likely conduct when Vz is exceeded even if current
is limited to something less than 1 mA, but the Iz (1 mA) spec on
the datasheet is the level they use to test it. And it will conduct
in the forward direction at less than 1 volt.

Ed
```
```On Tue, 28 Feb 2012 16:22:54 -0800, panfilero wrote:

> I want to use this 100V zener, and I'm trying to figure out how much
> current it draws when it's turned on, on the datasheet I see
>
> Vz "working voltage" is between 95V-105V with the condition Iz = 1 mA
>
> does that mean that as long as I make sure the zener is capable of
> getting at least 1mA that this will conduct when I go over 100V?
>
> here's the zener I'm looking at
>
> http://www.nxp.com/documents/data_sheet/BZX100A.pdf

No (don't you love it when all the responses agree?).

It means that if you put 1mA through it, it'll drop between 95 and 105
volts, depending on which one you pulled out of the bin.

Look at Figure 5 in the data sheet for an idea of what happens at
different voltages and/or currents: as the current goes down the voltage
does, too -- it just does so steeply.

Keep in mind that the whole plot shifts left or right depending on the
diode -- but keep in mind, too that the diode doesn't go from no
conduction at all to full conduction over the span of a microvolt.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com
```
```On Feb 28, 10:43=A0pm, Tim Wescott <t...@seemywebsite.please> wrote:
> On Tue, 28 Feb 2012 16:22:54 -0800, panfilero wrote:
> > I want to use this 100V zener, and I'm trying to figure out how much
> > current it draws when it's turned on, on the datasheet I see
>
> > Vz "working voltage" is between 95V-105V with the condition Iz =3D 1 mA
>
> > does that mean that as long as I make sure the zener is capable of
> > getting at least 1mA that this will conduct when I go over 100V?
>
> > here's the zener I'm looking at
>
> >http://www.nxp.com/documents/data_sheet/BZX100A.pdf
>
> No (don't you love it when all the responses agree?).
>
> It means that if you put 1mA through it, it'll drop between 95 and 105
> volts, depending on which one you pulled out of the bin.
>
> Look at Figure 5 in the data sheet for an idea of what happens at
> different voltages and/or currents: as the current goes down the voltage
> does, too -- it just does so steeply.
>
> Keep in mind that the whole plot shifts left or right depending on the
> diode -- but keep in mind, too that the diode doesn't go from no
> conduction at all to full conduction over the span of a microvolt.
>
> --
> Tim Wescott
> Control system and signal processing consultingwww.wescottdesign.com

got it, thanks!
```