Reverse Voltage Protection for Development Board

[Luis Estrada]

That's a KiCAD thing, I didn't even notice it lol! But yea, I see it is kind of an overkill, I just wanted to learn more about circuit protection as new EET grad.

[gnuarm]

That's a KiCAD thing, I didn't even notice it lol! But yea, I see it is kind of an overkill, I just wanted to learn more about circuit protection as new EET grad.

Nothing wrong with that.  Part of the protection problem is there are so many solutions, so many it is hard to know when to use what. 

A design I'm involved with is using a $4 chip and four FETs to select between two power sources.  Yeah, a bit of overkill.  The guy designing it never saw a Linear Technology part he didn't like.  The parts are good, but not cheap.  He had a $3 input protection chip and two FETs to protect against over and reverse voltage, when a diode would do pretty much the same job (everything being "protected" already had nearly as high a voltage rating).   He is also using a $4 switching regulator when a $0.50 part would do the job.  Why?  He says he knows "the LT part will work" as if the other regulators don't.  Whatever...

[Luis Estrada]

Yeah I understand, this project is not so critical. It's just a Development board for a PIC18F45K50 mcu, which works at max 5.1 V so I wanted to make sure it didn't get damaged. I did some calculations and the Diode will do fine.

[Terry Bites]

I use 64 bit Microcap11. It would use 12 but it keeps crashing on win10 pro.
https://www.spectrum-soft.com/download/download.shtm