stoooooopid question

[DWBH]

  if I don't have any 2N5457's, can I use 2N5458's? 

[boyersdad]

Most likely yes. In a lot of instances it will be fine. Look at the datasheet for the 2n5457 and 5458. I believe the main difference between them (and the 5459) is the amount of current they can source...

[DWBH]

Cool. I saw tha the datasheet, and it was the same for these two, so I figured there shouldn't be a problem. Anyway, I thought I'd better ask.

[R.G.]

When a semiconductor maker cooks up a batch of JFETs, it's always a bit of an enigma as to what will come out of the oven. What they tend to do is to cok up a batch, aiming for the middle of the characteristics in the spec, then test them all. The high gain, low current ones get to be one part number, the mid gain, mid currents another part number and the low gain low current ones another part number. They hope that there aren't many that fall off the edge and don't meet any of the specs. It's a lot like cooking up a batch of walnut brownies and selling some as "soft and chewy" and other as "crispy". All walnut brownies, but with different spec points. We could state with some certainty that these will NOT meet the specifications for pecan fudge. With some good luck there are customers for all of the "part numbers" in the brownie family.

[GREEN FUZ]

Interesting. I didn`t realise semiconductor manufacture was so arbitrary.

[Pushtone]

I love this pic from Mr Huge's gallery.

Can it get any more raw?.

TRANSISTOR
http://aronnelson.com/gallery/MrHuge





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[96ecss]

I always tell my students "the only stupid question is the one you DON'T ask" I hadn't considered swaping 57's for 58's but now I know. Plus I got to read about how JFETs are made. Thanks for asking.

Dave

[DWBH]

Well, I was to buy some 2n5457's to swap with some J201's on my bsiab. When ordering, I bought 2N5458's instead...