Reverse polarity protection: P channel or N channel MOSFET ?
Topic: Reverse polarity protection: P channel or N channel MOSFET ?
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Location: United Kingdom
Hofstadter's Law: It always takes longer than you expect, even when you take into account Hofstadter's Law.
Re: Reverse polarity protection: P channel or N channel MOSFET ?
Feb 10, 2014, 09:23 am
You can use that circuit without the resistor and zener diode if you can guarantee that there will never be transients on the 12V input that take it higher than the Vgs rating of the mosfet (20V for the one you have chosen).
The mosfet you have chosen is IMO not suitable for 3A load current because it is likely to overheat at that current. You need a mosfet with either lower Rds(on), or higher heat dissipation capacity (for which you will need a mosfet in a larger case style such as SOT223). Or two of those in parallel.
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