Are MOSFETs Static Sensitive After Soldering 100K–1M Gate-Source Resistor?

Hi - Is it just the gate on a mosfet that's static sensitive? In other words, once a high value (100K - 1M) resistor is soldered between gate and source, they'll be pretty much static-proof?
Thanks,

I'm not an expert on ESD protection, but here's what I've seen.

I wouldn't trust a resistor by itself.  Even if there's no current flowing through the resistor, you're still raising both ends of the resistor and the MOSFET gate could be damaged.
I'd prefer a series resistor, plus clamping diodes between the gate/drain and the gate/source.  That way there's no way for the gate to be more than 0.7V higher or lower than source or drain.  ICs often use diodes in this way to protect their inputs.
For fun, take a look at the MC1489 RS-232 receiver circuit on page 2 of  https://www.ti.com/lit/ds/symlink/mc1489.pdf   RS-232 is designed to survive nasty electrical environments.

It's a bipolar circuit, but it uses the same principles.   Input A has a 4K Ohm series resistor.  There's a clamping diode so that the transistor input cannot go more than 0.7V below zero volts.  If Input A goes above 0.7V, the transistor base-emitter turns on and serves as a clamping diode.
Hope this helps!

Ok, gottit! Thanks v much!

Graham
Despite its apparent simplicity there are a couple of factors you need to consider when using a resistor for surge/spike protection. Every resistor has a maximum voltage rating (100V for 0805)- exceed it and you are likely to experience a flashover, arcing between the contacts of the resistor, bypassing the resistor entirely, and likely damaging the resistor beyond repair.Second is energy dissipation. Different technologies are more adept than others. Metal film is not particularly good. There are some resistors rated for surges (also in SMD) although I haven't really put them to the test. The favourite amongst us old-timers are carbon composition resistors which are only available as through hole components. Sometimes hard to source these days, Newark carries the Multicomp range. At lower resistances (less than 100R) 1/4W work OK. But for resistances above that 1/2W are needed. In our testing the 1/4W would split in half with the energy dissipated.P.S. I think the 100K-1M resistors you talk about are way too high. Remember, the MOSFET has a capacitive input, and the RC rise time at the gate will turn the transistor on very s-l-o-w-l-y.P.P.S. You should still use the diodes as suggested by John, or even some other energy absorbing device like a MOV or transzorb (which will add to the capacitance at the gate)

Thanks!(Maybe EEWeb should have a competition for Something That Is As Easy As It Looks  : )