Re: Lowest rds on mosfet available
You should first quantify "very high" current and then
figure just how much voltage drop and switch Pdiss
this rolls up to, per ohm Rds.
Then, Digi-Key / Mouser / Allied / etc. will give you
parametric selection "choosers" that you can assign
acceptable BVdss, Ron value ranges to and sort as
you see fit.
You might like to look at the EPC GaN FETs if you
are able to handle their PCB attach; they have no
package or wire bonds to add to net Rds. Beware
however that EPC plays some games with current
handling specs (like, the advertised ratings are
narrow-duty-cycle and the FETs (their solder balls)
cannot possibly handle the rated current at the
rated temperature at DC - by a factor of 10 or more).
Beware also that the PCB may contribute more to
on resistance than the FET itself, when you are in
the sub-milliohm range (see copper sheet resistance
vs weight, and the realities of routing).
10V and 1mOhm allows 10kA which is a lot of juice.
100A and 1mOhm is 10W power dissipation in the
switch, which is not much for a fat FET. Not like
0.37mOhm is liable to be -that- much better, at
least in this ballpark. Quantify.