I have an application that I need to add reverse polarity protection on but it needs to be extremely efficient. My understanding is that a P FET or an N FET would be more efficient then a Schottky diode. How or why would I pick between using a P FETor an N FET as a protection diode? I’ve heard that N FETs are cheaper then P FETs, is that true and what other considerations should I think about when choosing between a F FET and an N FET? Thanks in advance.

 

What kind of FET are you referring to? JFET, MOSFET, MESFET, ...?

 

Perhaps this helps: https://www.infineon.com/dgdl/Rever...2.pdf?fileId=db3a304412b407950112b41887722615

They have two solutions, one using N-Channel MOSFET, and another using a P-Channel. You can also see the pro and cons.

 

You can use an N-MOSFET with the same simple circuit as a high-side P-MOSFET, but it must be connected in the common/return line.
This means the voltage source and the load must not have a common ground connection.

N-MOSFETs are indeed cheaper than P-MOSFETs for the same voltage and current rating.

 

What kind of FET are you referring to? JFET, MOSFET, MESFET, ...?

MOSFET. Most likely for a 3.6V battery. From what I read those are likely the best solutions but certainly open to suggestions Thanks to everyone for all the comments and advice!

 

Most likely for a 3.6V battery.

Since it's a battery I would presume you could thus use an N-MOSFET in the negative lead.
But the MOSFET must be a logic-level device that will fully turn-on with a Vgs of 3.6V [Vgs(th) less than 2V maximum).

Circuit here:

Simulation below: