I'm building a reverse polarity protection circuit using an N-channel MOSFET (see figure below)

Reverse Polarity Protection

For the battery I'll be using an 18650 cell which will range from 4.2 - 3.3V. The max discharge of my circuit will be about 10A. I'm currently looking at this MOSFET. The specs all seem to fall within my parameters but I have a feeling that there's no way a MOSFET this small could provide that much power; am I just over thinking this?

  • \$\begingroup\$ insufficient details , not over-thinking, also duplicate question electronics.stackexchange.com/questions/34915/… \$\endgroup\$ – Sunnyskyguy EE75 Apr 6 '17 at 16:54
  • \$\begingroup\$ Max current implies you have massive heatsink. Do the thermal calculations with duty factor and Rja \$\endgroup\$ – Sunnyskyguy EE75 Apr 6 '17 at 16:57
  • \$\begingroup\$ Missing charger? which needs 2 FETs N,P, \$\endgroup\$ – Sunnyskyguy EE75 Apr 6 '17 at 17:19
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    \$\begingroup\$ Does FET Drain-Source look reversed to you? \$\endgroup\$ – Sunnyskyguy EE75 Apr 6 '17 at 17:34
  • \$\begingroup\$ I was thinking the same thing, but I'm seeing this setup elsewhere too. \$\endgroup\$ – Sam W Apr 6 '17 at 17:36

According to the safe operating DC operation curve you are right at the limit for 10A at 25C. So I'd say it's not going to work for you. Also at 3.3V the thing will be barely on. Even 4.2 it won't be saturated.

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