Folks,
ON Semi has just end-of-life'd their whole slew of electret microphone JFETs, TF202, TF252 and TF262. Other types from Panasonic for pyro sensors have more than 10x the bias current, can't use those.
Does anyone know another manufacturer that makes JFETs for electret use in 3-VTFP (SC106)? Preferably operating between 100-200uA.
-- Regards, Joerg http://www.analogconsultants.com/
Oh, you and your boutique parts. It's probably some Chinese company now.
-- Tim Wescott Wescott Design Services http://www.wescottdesign.com
It wasn't boutique at all, it was a mainstream ON Semi line of parts and they seem to have axed the whole enchilada. It almost feels as if a favorite restaurant said "We ain't serving fries no more".
One of the issues aside fom the low current is the knee. Most other JFETs aren't very linear when operated at around 1V Vds.
-- Regards, Joerg http://www.analogconsultants.com/
Purchase a lifetime supply. Verical has 7M in stock.
--
Thanks,
- Win
My client would prefer not to have to do that. It's a brand new product idea and it might or might not fly. Wouldn't be good to sit on umpteen reels of those JFETs if it doesn't.
I have seen other microphone JFETs but they were Japanese or Korean and not sold over here.
Frustrating. Now I'll go looking for something else I also need, a beer brewing starter kit. Much more fun :-)
-- Regards, Joerg http://www.analogconsultants.com/
Close package sizes
Cheers
If it makes any difference, there are a number of packages with close body size - SOT113, SOT623F, SC105, SOT723, SC150......
SOT883 packages aren't discontinued.
I don't see an issue with immediate availability - these are still on lifetime buy status, and in stock most places. Just don't pick a Fairchild sub......
You're discrete options may be running out.
RL
Had resrvations - UTC has no NA distribution. You'll soon be able to buy many parts in China long before or after they are available in NA. There's just no local market volume here, anymore. Almost like the UK mfring collapsing in the last century.
UTC is the only vendor labeling this case size as SOT113 - it is not a true European registered part size (as all valid SOTxxx cases should be) - but UTC publishes a drawing, so I've included it in lists of xref smd mech parts.
SOT523 can't sub UTC's SOT113, unless there's more room. SOT523 is
1.6mmsq rather than 1.4mmsq, with gull-wing leads (SOT523F is flush). SOT623 is closest, but needs F to indicate it's not gull-wing. SOT723 is smaller (1.2mmsq), with no gull-wing version.RL
They were Sanyo, when ON bought Sanyo. Not exactly mainstream, ever.
RL
Thanks, Martin, I have copied that link. Some I wasn't aware of yet.
A few would work after circuit mods, such as the TF2123. But unobtanium in the US. So we'll do a larger "hoarding buy" and then if the whole concept works have to source in Taiwan.
-- Regards, Joerg http://www.analogconsultants.com/
Maybe that trend turns around early next year :-)
Most politicos are blind. Like the leftists in California who now upped the minimum wage by 50%. Some companies have already begun to leave, along with the jobs.
SMT standardization has never really worked well and I am afraid never will.
We will have to do a relayout, no doubt. Likely also have to establish a purchase path into Taiwan or another Asian country. I am still hoping that one of the US distributors is smart enough to offer such parts. But maybe not.
-- Regards, Joerg http://www.analogconsultants.com/
With huge stocks at conventional distributors, plus 7 million pieces at Verical (!!), the TF202 is not likely to become unavailable for years. If your product becomes a success sometime in the next few years, then a lifetime purchase can safely be made. These are really cheap, 6 cents qty 10k.
--
Thanks,
- Win
Tell it to the IPC
All standards follow practice, innitially. The SE Asian developers were and are in the forefront of packaging. There's no reason why this body couldn't have been recognized by Sanyo or UTC as an SC106x (there are 4 package thicknesses recognized by Jeida), except that their datasheets were never revised from novel release.
When ON bought Sanyo, they didn't buy the vertical integration or good wiil. I'm not sure how that worked for Fairchild and Samsung, but expect that whatever is left will be scuttled if or when ON takes over there.
I expect you're folowing the fA IC thread. If everybody's doing it, there really isn't a practical design choice, unless you can steal parts from another unrelated mainstream application. (smoke detectors?)
RL
Yes, if regular supplies last at least a year which is about the time of testing we will be fine. Later we'll either have to source in Asia or I'll have to add a voltage boost circuit so we can use a more common FET.
In my book that is very expensive :-)
-- Regards, Joerg http://www.analogconsultants.com/
Won't help.
Not just Asians. I've had differences in same name packages between Infineon and Philips (now NXP). We got tripped up in the layout several times because of this problem. So now my layouter makes a new footprint for each part per datasheet, ignoring the official name.
Which doesn't make a lot of business sense.
Those are unfortunately too high in the knee. They don't become linear enough unless there's 2-3V Vds. We only have 1V. So I may have to design another converter ... ...
-- Regards, Joerg http://www.analogconsultants.com/
That's always interesting. Probably a 6" wafer design they decided not to transfer to 8" or some such thing.
robert
Probably more like "Well, we bought the manufacturer with the whole kit and kaboodle but this line doesn't make us enough money".
It's comsumer stuff, very tough to make money.
-- Regards, Joerg http://www.analogconsultants.com/
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