Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

help for zener datasheet understanding

Status
Not open for further replies.

yougarage

Member level 1
Joined
Apr 13, 2011
Messages
38
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,286
Activity points
1,599
Hello! I want to use a zener diode to protect the input pin of a microcontroller from overvoltages, but I really don't know which one to choose.
The pin is fed by a 2200 ohm resistor, and after that, the zener to ground.
I attached 2 sections of datasheets about 2 different zeners, they have very different values of Zzt, but i don't know which one is "better"
I don't really understand in practice what the Zzt value means...
For what I think, it's the resistance while it's in the breakdown region, so lower is better
is this right?
any advice is greatly welcome!
zener datasheet.png

zener datasheet 2.png
 

Izt means zener threshold current it is maximum for the particular rating shown in the data sheet
 

... they have very different values of Zzt, but i don't know which one is "better"

This is because the differential impedances Zzt have been measured at different break-through currents Izt. As larger Izt, as lower Zzt ; for relatively low currents the break-down characteristic gets steeper with rising current. I think the 2 diodes are comparable.
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top