I'm running a atmega644 at 3.3v and have 2 io lines available to the end-user, usable as digital in or out or as analog input. I will need to protect these lines from ESD events.
I found a few threads discussing how to do this with this post being very informative.
So I set out to find an appropriate diode. The signals are not time critical on these lines.
My best guess for the values are:
The Reverse Standoff Voltage is 3.3v
Voltage - Breakdown: 3.5 or 3.6
Problem is that there are only a few parts, can I go to breakdown of 5v?