Power protection circuit

Community PCB Design
1

Hello,

I want to use a power protection circuit on my board letting only 3.3V pass through (the other possibility is 5V that I want to block). Is the schematic below correct? Is it dangerous (especially for the Zener)? Is there any other suggestions/modifications or other advised schematics that can do the same job?

Thanks for your help!

2

This is a continuation of the thread started here:

posting.php?mode=reply&f=20&t=21595

Let’s only continue the discussion in the original thread.

/mike