> I wish to drive a IR LED at 40khz (essentially the Sony IR
> protocol),  somewhere between 50mA and 100mA max LED
> Ifwd

You'll find that IR LEDs can withstand many more times that for
short periods (eg data train pulses), leading to greatly increased
range or reliability in marginal situations. That current can be
sourced from a reservoir cap. A 2N7000 is rated to only 200mA
and you wouldn't be able to take full advantage of the robustness
of the LED if you wanted to

Joe
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