MOSFETs with gate-drive specs below 1.8 volts

Well, all the CMOS processes that use polysilicon gates could certainly make such a resistor. How does a five-or-six pin package work, though? Maybe a pair of resistors, one to the source, and another to the drain, would work (don't want to load the gate).

I was thinking of a resistor from source to gate, in the standard

Most mosfets actually have 4 leads, counting the tab. We show all four on our schematics. So steal the center (formerly drain) pin for the temp sense resistor or diode. Even easier.

I sometimes build an analog or software computer that models estimated Tj in real time, for a temperature based shutdown. That allows fets to be safely pushed a lot harder than just current limiting.

onsdag den 20. marts 2019 kl. 01.51.27 UTC+1 skrev John Larkin:

Actually I suspect that whichever way they fall out, they tend to bounce and stop upside-down. That would be very easy to test, but basically it's the boomerang cross-section.

What, they bounce and disappear. My lab floor has all these little specs, it's impossible to find.

Love it! Looks like the unijunction rules.

That's for class AB biasing, not for protection. I'd prefer the temp sensor to be terminated to the source, or have two pins of its own.

Or have some self-protecting fets that work right.

Pre-tin the pads, place part, apply heat to trace leading to pin. The flux apparently pulls lead toward pad, then liquid solder takes over.

I made the mistake of making a proportionally dimensioned footprint, rather than a human-scale footprint. :-)

Which means it's great after I picked up a hot air machine. Definitely recommended for anyone doing much of any SMT.

On that note, I use fairly small pads on 0402 (around IPC-7351 '_L' size), to reduce risk of tombstoning. Impossible to solder with an iron anyway, no loss there. ;-)

Tim

Don't forget the compl_i_mentary transistors one, too.

Which unfortunately I can't find. Anyone?

Tim

That's because they all end up in the "universe next door." They vanish from our reality and instantly re-appear in a parallel dimension with a tiny tinkle as they hit the floor in some other guy's lab, startling a nearby mouse. I saw it on the Twilight Zone.

Always pull four parts from stock to replace one on a board.

That works fine for a part that has one pin.

(If it doesn't stick to the iron.)

I was searching for a good SOT89 NPN transistor and found this.

onsdag den 20. marts 2019 kl. 04.02.27 UTC+1 skrev John Larkin:

I know, how about this one:

or this (EOL ofcourse)

this family looks interesting

Agreed, for folks who have a clue. Others would find that their gate drive was being scavenged just when the FET was running at maximum current, resulting in near-instantaneous transistor death.

Cheers

Phil Hobbs