Reverse Polarity Protection NMOS

Discussion in 'The Projects Forum' started by kewzj, Dec 10, 2013.

  1. kewzj

    Thread Starter New Member

    Oct 30, 2013
    Hi all,

    I'm currently constructing a protection circuit for a buck boost converter and I'm planning to use NMOS as the protection for reverse polarity. I stumbled upon a figure (attached together below) and I was wondering what are the parameters required to choose the diode protecting the NMOS which is involved in the reverse polarity protection at the return path? Besides, is it necessary to connect a resistor in series with the Gate of the NMOS involved in the reverse polarity protection?
  2. ronv

    AAC Fanatic!

    Nov 12, 2008
    I don't think the circuit on the left works because it is a source follower.
    What you need for the one on the right depends on the power supply voltage and the battery voltage.