In this short video, I explain when a Zener diode may not actually be a Zener diode, and why this may impact circuit design.

It's all about the breakdown mechanism in the diode. We know that the diode breaks down in the reverse direction, but there are two different ways in which this occurs.

Below about 5 or 5.5 volts its Zener breakdown. Above this impact ionisation progressively dominates.

So below about 5 volts it's a Zener diode but above this we should call it a voltage reference diode - but we all know what we mean by a Zener diode whatever the voltage.

So why is this important? It's because the temperature coefficients of the two mechanisms work in the opposite directions. So around 5 to 5.5 volts where they're both present, the overall temperature coefficient is much less, and if you can use a diode with this voltage in your circuit it will be more stable. Very useful!

More information so you can understand about Zener reference voltage diodes and their uses in electronic circuit designs can be found at: www.electronics-notes.com/articles/electronic_comp…

Information about the theory of operation and breakdown mechanisms:
www.electronics-notes.com/articles/electronic_comp…

Information about linear voltage regulators including some Zener diode circuits: www.electronics-notes.com/articles/analogue_circui…

Website homepage: www.electronics-notes.com/

Please don't forget to subscribe to our YouTube channel: youtube.com/electronicsnotes?sub_confirmation=1