I have a situation where I need to use a pretty stiff pull-up resistor on a mosfet gate because I'm going to use a comparator to turn it off, and I plan to limit the current the comparator sinks to about 5 mA. The N-mosfet source will be sitting at 15 volts and the gate drive comes from a voltage doubler. That's a bit less than 30 volts so the pull-up resistor needs to be in the 6k ballpark. I'm going to use the NTP90N02:
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Speed doesn't matter -- this is basically an on-off switch, so I have only to consider the dc behavior of the mosfet. The mosfet has to conduct ten amps. My question is, how much resistance can you put in front of the gate before it gets too weak to turn the mosfet on hard? Mosfet models don't address this, so far as I can tell. I haven't ordered the NTP90N02 yet so I can't simply experiment on it, but I remember other mosfets having problems turning on when the gate resistance gets into the tens of kilohms.