it feels like a real stretch to call sot-227 a sot package
-F

@Felthry y'all's posts make us do more web searches to figure out what y'all're talking about than most

...also we agree - it doesn't look anything like the small-outline transistors on the Wikipedia page and is also like five times the size?

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@packbat hah, sorry

but yeah i don't know why it gets the SOT designation, it's actually way more than five times the size of most SOT packages
-F

@Felthry no sorry - we look it up because we expect it to be interesting, and it is!

and wow, yeah, that's ... that's a really big jump in size and also if we're not mistaken a completely different mode of mounting? that seems like a meaningfully different category of electronic packaging

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@packbat yeah every other SOT package we're aware of is a surface-mount package but SOT-227 is not only through-hole but screw-mount
-F

@packbat and! there are three main categories of packaging: through-hole, surface-mount, and chassis-mount.

Through hole components have pins that go through holes in a circuit board, and are soldered into place on the opposite side of the board from the actual part itself. Examples of this are the common DIP packages, TO-92, TO-220, TO-247, and most of the common recognisable resistor/capacitor/diode axial packages

Surface mount components are positioned on top of a circuit board and soldered into place on the same side, and they can usually be much smaller since you don't have to deal with long pins that are super thin and right next to each other, nor do you have to deal with drilling very narrow holes--some surface mount components have a pin pitch (distance between adjacent pins) on the order of 0.2 mm. Examples of this are SOIC, SOT-23, SOT-223, DPAK (TO-252), D²PAK (TO-263), TSSOP, QFN, and the little tiny passive elements like 0805 and 0402 and 0201

Chassis-mount components are Large and generally high-power components (but sometimes they're things that are just convenient to have on the front panel--this is called "panel mount" but it's the same idea); they're meant to be bolted to the chassis of a device, not mounted on a PCB, and have wires going off to whatever other chassis-mount components or PCBs they need to be connected to. SOT-227 is an example of this; it's meant to be screwed onto a heatsink and then have wire leads going off to the PCB, though you can also screw a PCB directly onto the SOT-227.

-F&R

@Felthry *nods!*

we'd heard of through-mount vs. surface-mount; we actually hadn't encountered the idea of chassis-mount before - that's pretty neat!

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@packbat Sometimes things are just too big and bulky to go on a PCB! most mains-frequency transformers are chassis mount for instance, because otherwise they'd 1) be way too heavy and stress the pcb, 2) take up way too much board area (which isn't cheap), and 3) require having mains voltage on your PCB, which is Difficult To Deal With
-F

@Felthry *nods!*

It makes perfect sense! And also makes the SOT-227 even more completely different from the other SOT packages.

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@packbat yeah SOT-227 is designed for really high-power stuff and generally when you want high power you don't use SOT packages (though you can get away with a D²PAK or D³PAK and good thermal design), you go for stuff like TO-220 or TO-247 that are designed to have heatsinks mounted on them
-F

@Felthry ...but SOT-227 is designed to have a heatsink mounted on it too - we saw a load of SOT-227 heat sink results on DuckDuckGo when we searched the name

...what would you call it, if somehow you were given a chance to retcon its name without issue?

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@packbat yeah if we had a chance to rename it we'd probably give it a TO- number

And it's not quite the same; TO-220 and TO-247 are designed to have heatsinks mounted onto them, while SOT-227 is designed to be mounted onto a heatsink
-F