Why no H11F1 OptoFET?

NTE lists a crossover of NTE3085... Web-tronics.com shows them in stock, as well as weisd.com. Tried plugging it into Digikey with no avail. Mouser shows in-stock with their part number 526-NTE3085.

Hope this helps.

-Gordon

Farnell has some.

Graham

" snipped-for-privacy@gmail.com" wrote in news: snipped-for-privacy@k79g2000hse.googlegroups.com:

Thankyou. It does, a lot. As these IC's are expensive, (even H11F1's are in UK, the last were bought via a friend in the US), I'll only buy a few as I need them so I need to know I can get them again. If I can, I can get by. What's scary is the thought that something as useful as a FET optoisolator could vanish as if suddenly no-one thinks they are useful. Google shows many inventive uses for them, but if the makers decide they don't value any of that, it helps to know why they should not do so. I can't see how something with such a unique and powerful function could be replaced or made obsolete.

Eeyore wrote in news: snipped-for-privacy@hotmail.com:

So do RS. But for how long? I'm not thinking about the few drying pools left, I can raid a couple of those if I need (and I will, as the NTE3085 that Gordon posted about costs at least double). I didn't raise a new thread to find a handful, but to question what looks like the end of the line for something that showed every indication of being new. It reminds me of a news story about a village that grew daffodils for a show, and whose occupants woke one morning to find someone had cut all the buds off during the night. This obviously isn't the dying end of an old product no-one needs anymore, so what's going on?

innews: snipped-for-privacy@k79g2000hse.googlegroups.com:

It concerns me as well... but that's the way of the world anymore. I remember a time when you could get pretty much anything you wanted at RadioShack... but the RadioShack of today is nothing like what it was ten years ago. Used to be once upon a time that people were excited about this hobby, and you saw all sorts of incredible and inventive things being done. All of that's gone now. The beancounters have taken over. Electronics isn't sexy anymore.... so if some large corporation isn't buying them by the tens of millions... the profit margins are too low to even bother with catering to a virtually nonexistent hobbyist market.

Expect to see lots of handy things disappear as time goes on... and as modern manufacturing moves more and more toward SOICs and ASICs... expect to see our hobby relegated to the complete, utter fringes of society.

Glad I could be of help.

-Gordon

But are they sensible uses ?

If its possible to do it with a cheaper part you can be sure that's what will happen. No demand for the part and it'll be discontinued.

The days of designers using boutique parts have vanished mainly. What application are you using them in ?

Graham

Eeyore wrote in news: snipped-for-privacy@hotmail.com:

Yes. Go look at the H11F1 datasheet, that alone shows some uses that make them worth saving.

Your talk of 'boutique' parts in this case is stupid. If you beleive that logic you'll soon be advocating the censure of mere fripperies like the thyristor and the triac.

You shouldn't need to know my application to justify the need to retain such a part, and I shouldn;t have to tell you. What do you seek to do? Ask me to puty it up su you can knock it down? The makers didn't need your justification to make the part in the first place, so why does your judgement now depend on mine? For your curiosity, I will answer: a laser diode modulator. And don't tell me there is an easier or cheaper way to get a shunt modulator that has excellent isolation and linearity than this, because there isn't one. An optoFET is the only way to do that cheaply with a very low parts count. I've seen other designs in lots of commercial designs, and most of them are horrible. In their effots to be cheap they've reduced all the safety and linearity they want to brag about, and one little optoFET could have made a LOT of difference.

" snipped-for-privacy@gmail.com" wrote in news: snipped-for-privacy@y80g2000hsf.googlegroups.com:

Eloi and Morlocks. >:) This wouldn't be the first time I've been reminded of those. Wells was right.

Whose ?

I was hoping you'd say which ones were sensible in your assessment.

Hardly. They're used by the bucketful.

Because I'm curious why you need it and maybe I could have offered another solution.

You're getting a bit pissy over a simple question here. If you don't want to tell me, that's fine.

Graham

Eeyore wrote in news: snipped-for-privacy@hotmail.com:

Whose do you think? Did you read any previous posts on this, or did you drily insert your arid scholarly wit in the assumption that you know FAR too much to actually read a post before answering it?

FAIRCHILD. That would be a good start.

What is this, a masterclass?? Try the sample/hold with very low leakage and no feedback to the controlling system, or the noiseless AGC/switch/fader for audio, or the isolated laser diode modulator.

No, I'm getting pissy over your dry aura of scholasticism that has no grounds for its high and mighty airs. And I did tell you. I guess you didn't read that either.

Eeyore wrote in news: snipped-for-privacy@hotmail.com:

Not interested. I'm not so blind I can't see alternatives, or that your offer is really based on your desire to show that I'm wrong. Don't bother. If you want to impress, show why the makers of that IC, Isocom, Fairchild, and the form NTE that have emulated it and justify more than double the cost see fit to make them in the first place. If you can show why all those people are wrong, I'll be mightily impressed, believe me.

I was asking you. You didn't specify and I don't believe in making guesses. How about specifying which uses you think are uniquely suitable to opto-fets ?

Graham

It could very easily be.

I have no application for that. The absence of charge injection is cute but everything else could be done in any pratical application I can think of with simple level shifting.

It's fairly rubbish for audio. More than about 75mV rms across the fet and you get distortion. VCAs do much better and for ages I've also been using opto-coupled resistors. These are vey nice and a lot cheaper (as little as 20 cents in China) and even match quite well.

Graham

More like practical real world low-cost design experience. I DO NOT use silly frivolous pricey boutique parts.

You remind me of the guys (so-called designers) who would get all excited over RS introducing some new exotic expensive part into their catalogue who then felt obliged to design it in to their employer's products and design the company into financial failure.

Graham

I rather doubt that. They probably picked up some equivalents and just re-marked them, RS components style.

Because they could ?

Wrong about what ? Once upon a time there was demand and they made a profit. That's good business. If there's no demand now they'll stop making them. That's good business sense.

Incidentally, if you look at the applications on the Fairchild data sheet, many are analog. Much of that is done in DSP now. I can't imagine anyone making a filter tuned with opto-fets these days when you can do the same thing more accurately with better THD and noise figures and cheaper too in DSP.

Also, if you must, these optically coupled resistors are about 20 cents....

Graham

innews: snipped-for-privacy@hotmail.com:

Dude... seriously. Go take a prozac or something. I get the impression Eeyore is only trying to help.

Eeyore wrote in news: snipped-for-privacy@hotmail.com:

Given only two or three firms mentioned, and one that comes up for most Google results, you didn't have to guess, you had to think.

As for 'unique': unfair question, and you know it. There are often other ways to do things, the question is which is best. A lot of things justify this part type, as the makers obviously realised. If a lot of people choose not to use them, fine, but when you want the resistor-like behaviour of a FET without the complications of a bipolar type, and the total electrical isolation that this part offers, an optoFET is the best part to choose.

You're asking the wrong question. Instead of asking me why the part should exist, ask the makers. All of them. They can answer better than I ever can. All I ask is that having made them, I'd like to know why they might stop, having gone through RoHS adjustments in a clear effort to continue, and what replacements might be found. Gordon chose to help, you chose to argue. I accepted the invite, but it gets old fast. If I'm to argue further I want it to be with some better reasoning and attention than you've shown.

Eeyore wrote in news: snipped-for-privacy@hotmail.com:

Wrong. I try to use basic parts where possible. I just happen to consider an optoFET as a basic part, just as a bipolar optoisolator is a basic part. I don't like using new unusual parts with complex or exotic special functions either, but you can't see that can you? All you can see is someone who knows less, therefore must know virtually nothing. You're all judgement, but so inattentive of stuff in the posts you're answering, that you look more ignorant then you should.

" snipped-for-privacy@gmail.com" wrote in news: snipped-for-privacy@q75g2000hsh.googlegroups.com:

I don't. I felt like arguing with him. Your help was useful. His wasn't.