IRFP240 source?
 

Are the IRFP240s becoming scarce now? I couldn't find them on mouser or anywhere else "reputable." Any suggestions for where to get these? Maybe my mouser search was bad? Or maybe someone has had good luck with a particular ebay seller? I'm looking to get quite a few so I can match them myself.

enter IRFP240pbf in the search engine

Farnell still has 2439 of them in stock.

Ah, ok. Not a great search engine, is it?! Thanks!

While I'm on the topic... Any guidance on what number you need to purchase to get good matches? Let's say you need to match 4 closely. You need to buy... 20?

Similar question on the IRF9610s although I would guess the answer would be about the same.

Depends upon how closely you want them to match -- if you purchase a tube you should get enough devices for 2x 4 sets +/- 0.02V.

I found that within a tube, when you match for Vgs the transconductances generally line up pretty well.

Sorry for the newb question, but how many in a tube?

25 pieces

I've used these as an alternative to the irfp240, they work pretty well. You should have no problem matching 4pcs within a tube, I'd be skeptical purchasing semis from ebay; matched or otherwise.

FQH44N10_F133 Fairchild Semiconductor | Mouser

You need matches only for the ones in parallel. Most of the time 0.1V
at the operating point is good enough, and you can probably get 5 groups of
4 out of a tube.

:cool: