Most of the good MOSFETs I'm aware of are SMT only, which is not beginner friendly. 2N7000 through hole is extremely available damn near everywhere. All companies have a clone of the venerated, classic MOSFET.
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Honestly, if you're doing through-hole on ESP32, I suggest using a resistor + 2N2222 BJT instead of the MOSFET. But I think 2N7000 is easier (fewer parts, in particular no resistor needed). But that's a 5V design.
The 2N2222 also requires you to leak a decent amount of current through the Vbe / Ibe (while 2N7000 is like 1uA or less leak Vgs / Igs).
But... 5V and 2N7000 Jellybean + throughole is really easy to use. Its definitely a big advantage to Arduino IMO, and I'm glad that they're keeping the 5V driving capability in this newest version.
Yes, you can be careful about this and order the right part number to get a newer protected-gate version, but at that point please do us all a favor and specify some non-stone-age part.
Few? Tons of MOSFETs have no ESD protection, because that ESD protection diode has uA levels of leakage current in practice. Both MOSFETs discussed in this subthread (IRL540 and AO3401A) are both unprotected MOSFETs that blowup from ESD.
In fact, no one has even listed an ESD-protected MOSFET yet.
> Yes, you can be careful about this and order the right part number to get a newer protected-gate version
Unprotected MOSFETs have nothing to do with "old" or "new". Its because that protection diode has a number of characteristics (in particular: sucking currents in a different direction than expected and changing the circuit) that needs to be carefully considered.
You can't just replace unprotected MOSFETs with protected ones and hope that your circuits work. You very well could be shorting out some circuit inadvertently.
The 2N7000 is significantly worse than other MOSFETs. I don't know if that's because it's older, because its fab process is worse or was worse at one time, because it's easy to get those TO-92 legs into trouble, or just because of the die's low C_iss, but it's one fragile little bastard. The 2N7002 seems to be much better!
> Unprotected MOSFETs have nothing to do with "old" or "new".
Yes, they do, because the 2N7000 is older (1986) than integrated gate protection devices! Anything you see with them isn't a "true" 2N7000, even if it might meet the JEDEC spec sheet (which is rather hard to turn up...). Modern versions might have protection or might not (check the letters at the end of the part number... and hope you've got the right era of datasheet... and hope you've got the original MPN and don't have to read the condensed markings on the parts themselves... oh and hope you know the actual manufacturer!), but if they're older then they certainly won't have protection. So it kind of is an old (nope) versus new (maybe) thing.
> You can't just replace unprotected MOSFETs with protected ones and hope that your circuits work. You very well could be shorting out some circuit inadvertently.
Okay, technically, yes. In practice, no. Enhancement MOSFETs are usually used for power/switching applications, which won't care one damn bit about a silly diode, or in feedback loops for analog applications, which again won't care much. For various reasons, JFETs and depletion MOSFETs are usually preferred in analog-land, along of course with ICs. That's not to say you don't see discrete enhancement MOSFETs, but it's very, very uncommon. (And when I try to design that sort of stuff, I always seem to get stuck on not being able to find a FET without the pesky diodes built in. Sigh.)
August 2022 part. Unprotected MOSFET. Top-of-the-line, modern technology with 0.003 Ohms Rds, 157 Amps supported.
Protected vs unprotected has nothing to do with old or new. And yes, the specs on the 2N7000 suck, but who cares? It gets the job done and is the dirt-cheapest part. Beginners don't need performance, they just need lots of parts to play with, so cheapness probably takes priority.
> Also, manufacturers occasionally get sloppy about noting their existence
What are you talking about?
Any MOSFET with ESD-protection has a Human-body model (HBM) ESD specification. Probably in the realm of 2000V, or +/-1700V, depending on how the protection diode works.
TI btw makes a ton of ESD-protected MOSFETs with 4000V ESD and like 50nA of leakage. But they're much costlier, and of course surface-mount only because that's what pros use in practice. (Beginners definitely prefer through hole so that it works on breadboards, which is another reason to use 2N7000).
TI Part for reference: CSD17381F4 / https://www.ti.com/lit/ds/symlink/csd17381f4.pdf
You can tell its ESD-protected from the HBM test and CDM test. Also, the circuit model shows the protection diode.
While I love digikey’s parametric search, I’ve gotten feedback from more than one budding hack after that it is “too complicated and confusing”