Usually I can get by with jelly bean amps but not this time. Offset should be well under 1mV but most of all the input noise must be under
5nV/sqrtHz. Supplies +/-15V, TSSOP or SOIC, quad package. The OPA4227 fits the bill nicely with plenty of margin. Then came the awakening: Out of stock at Digikey and Mouser. Same for its faster brother, the OPA4228. Big red flags went up.
Could the OPA4227 be falling from grace for some reason? If you know what replaces it I'd appreciate a hint. I am looking around myself now but want to pick something that's going to be around for a couple of decades.
Might add one here that can work: AD8674. In stock but rather expensive. Around $4. Ouch.
The only guys I didn't try was National. Their web site repeatedly pulled a blank after narrowing down the opamp selection. They really messed up their site, big time. Anybody listening at National? I guess not...
Do you remember when the National Guys advertised the web page as "no thrills"? Now they want me to download some flash thing, that I have always to deny by clicking when entering their site.
Reg. TI: rumors are that a lot of BB products where moved to an asian site and bigger wafers and to a different test site. It seems that things didn't go that smooth as expected. Look at the lead times of the ADS8344 e.g. Constantly "26 weeks" since last august. INA114 isn't better, and so a lot of other chips...
IMHO they seriously messed up their site. Ok, the flash gimmick can be ignored. It's just one extra and unnecessary click. But now I frequently encounter a blank page when trying to dive into detailed product listings, repeatedly. After 2-3 times I move on to a competitor. Since their, ahem, "web site enhancement" I have not designed in one single National part. That was very different before. Maybe it's just me but the truth cometh onto the table with their next quarterly financials.
And no, I will not take the typical web kiddie excuse that I have an incompatble browser. A site that only works with a select few browsers is IMHO a poor job.
That has me concerned as well. It would basically leave AD and LTC as the contenders and their products tend to be high cost. Not that I find them overpriced in any way, it's just that I don't usually need the extremely low offset voltages they offer. It is like buying a Porsche in the US where you can't drive faster than 65mph anyways. Yep, I sometimes miss your autobahns.
I remember when the National data books were like the Holy Grail of data books. Vendors used to have a "literature room", where you could just walk in and help yourself to any data books they had - the Nationals were always picked clean when the slow guys got there. :-)
I was working in Orange County, CA at the time and was almost within walking distance of Arrow, Future, Newark, and a bunch of other vendors - Everyone had a shelf full of data books. Nowadays, they don't even _print_ them any more! )-;
this is exactly what will happen to the remainder of our technical dtabases also.
as this stuff evolves ever more quickly, they just cant spend time/money/trees to put it all into hard copy! (at least not for public distribution)
some legislation (omigod!) should be initiated to help (FORCE) the brilliant minds to deposit at least a copy of their works into soem majestic government vaulted room filled with currently useable data storage devices.
a duplicate room would be created every say 5 years with new technology and the first room's data replicated into the new media.
otherwise, the lack of continuity from genereation to generation will be fragmented at best.
so, who knows where to find a lenticular refractor lense for a 1740 duGenereaux magnification device? or what the curvature and specs are? or even if they existed?.....
And that is why those are on this here shelf and will remain there until the slide rule falls out of my hands. Then, hopefully, they'll migrate into the hands of another engineer. The web clearly is not a reliable replacement for databooks. Nor is it fast enough the way most semi mfgs have "organized" their sites.
Yesterday I was picking parts out of a well worn 2003 TI selection guide. Much faster than online.
Some, like TI, have a service where you pay the printing and shipping costs and then they'll have one printed up and sent out to you. Makes perfect sense to me. Many moons from now other companies might realize how practical that is. Or maybe they don't.
In the same way lots of people have (finally) come to realize that their newfangled PDAs aren't all that useful and are going back to, gasp, daytimers. I've always stayed with my daytimer because it works.
we have many stock for opa4227,but could you let me know the exact suffix you interest? there is have many suffix ,eg. opa4227ua,opa4227pa, we have opa4227ua, hope to hear from you .
we have especialized in electronic over 19years.most of our customers of china distribute repairs line and graduate school ,we also have plenty of overseas customers,pls find our reference in enlosed documents. because we have many years experience for repairs line,so we can convince you of our service,we hope to establish long-term trade relationships with you. since 2001,we became a member of ERAI.
pls give me e-mail if you need any component, sepeciately stop-producted,hand-find, MY msn: st firstname.lastname@example.org skype : michaelvisual
huandong electronics ltd.
Usually I can get by with jelly bean amps but not this time. Offset
most of all the input noise must be under
or SOIC, quad package. The OPA4227
margin. Then came the awakening: Out
its faster brother, the
OPA4227 be falling from grace for some reason? If you know
I'd appreciate a hint. I am looking around myself now
something that's going to be around for a couple of
-------------= Posted from Ugroups.com =-------------
---= Fast & Free Web Portal to Usenet Newsgroups =---