Photodiode case

I've had 13 motorcycle crashes on the street, about half involving cars, and literally hundreds in the dirt, a few of which involved trees. My wife is a speech pathologist who has worked on too many guys who will be goofy or veggies for the rest of their lives, so I sold my bikes. Besides, the drivers are way too scary these days.

But I still ski.

John

Our 1988 2nd edition jellybean JFET opamp was the LF411, which is basically the unity-gain-compensated low-supply- current regular-speed, newer version of the LF357. When we looked for a replacement jellybean for the 3rd edition, after going all around, we came back to almost the same part: either an LF411 or the LF412 dual version, and the LF412A for better accuracy. This was because the newer, interesting opamps can't be used with +/-15V supplies. Yes, we'll have a newer +/-5V-supply jellybean opamp, but the LF412 nicely fits the bill for a routine opamp. Either that or maybe the TL082, etc., except it's really an inferiour amplifier to the LF412. I see the LF353 is also rather cheap and well stocked. So there really has not been much evolution in 20 years!

Now, THAT sounds like fun! Good luck with it.

Well, I've come to the same conclusion, but you used a much more creditable method...I just have drawers full of old parts. ;)

The 411/412 and 353 are noisy like the 351, iirc. The 356/357 were quieter. The good behaviour, +- 15V supplies, and (especially) the 2 pF input capacitance were extra nice, even if the Vos performance wasn't that great. The +-15V is really important for dynamic range--I hate losing 9-10 dB by using +-5, and losing 15 dB for the privilege of using

+5/0 genuinely stinks. (The old +- 150V tube op amp supplies look better all the time!)

Thanks. I'll know tomorrow whether the I-V characteristics are any good. If they are, we'll try making some waveguide-coupled devices in November. Our Ni/NiO/Ni devices have responsivities about 0.08 A/W at present, and there are lots of efficiency tweaks to go, but they need

100 mV of bias. We're trying for a 100x decrease in overall I/O power for computers--we hope to show that you can get to 40 uW/(Gb/s) end to end, including laser power. The problem is that it's really hard to simulate the device performance, due to multiple length scales--the tunnel junction is about 2 microns long by 400 angstroms wide by 25 angstroms thick, and so to get any resolution down in the junction region, you have to do simulations in 30 GB of memory that take days to run.

Cheers,

Phil Hobbs

Actually, Jim looks more like Dick Cheney, but fatter. ;-)

Cheers! Rich

That don't count. Mine's also a "Rice Jeep".

What I meant was this kind:

--
Regards, Joerg

http://www.analogconsultants.com/

I've dropped my bike, driven it off a cliff (inadvertently - it was an unknown hill with a sheer drop-off into thorn bushes on the other side), burned out the clutch, dropped it again, etc., but I've only ever had one actual "collision" with it: I lost it just enough in a left turn to sideswipe a parked car. I was able to blame the first drizzle of the season, but got really paranoid in turns after it.

They tagged the car owner, because it was a "No Parking" zone. ;-) (they sewed me up and I got 30 days' light duty. ;-) )

Cheers! Rich

I've driven one of those... it's like driving a luxury car.

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
         America: Land of the Free, Because of the Brave

Sure is. Except that I got 20mpg with an "Executive Edition" Crown Victoria versus 8mpg with a Chevy Dually.

--
Regards, Joerg

http://www.analogconsultants.com/

I really don't get it why they do that. Well of course I know but I still hate it. Recently I've seen a new +-15V amp marketed as "high voltage" (I think it was National or Linear, or even AD).

robert

Le Tue, 30 Oct 2007 15:15:46 -0700, John Larkin a écrit:

I'm doing paragliding (a lot). The last ski teacher I talked to went nut when I told him: Skiing? No, thanks. It's far too dangerous because it's way too close to ground.

Comparing both, stats are not in favor of skiing.

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Thanks,
Fred.

Meanwhile I'm sitting on 20 or so LF455/6/7 which obviously did not survive the intervening 20 years, so I hope I can find the right paper book (I have some stashed here, and some elsewhere), as National does not have the datasheets for those on-line, and I'm not over-fond of the "pay money for datasheet" people. My op-amp book stops at LF453...

Of course there's also the "do I want to use them at all, if they have been weeded out of the stream" consideration, but I hate to waste things (other than storage space, evidently).

--
Cats, coffee, chocolate...vices to live by

A google search on these part numbers brings up exactly nothing opamp-like, which I've never experienced even for long-gone components.

Yeah, those are well-known.

robert

Those were nice parts. I still have some left too...iirc they're in the

1989 data book. I'll look them up and see if I can post the datasheet--basically they were the LF3xx series with the current limit resistor pinned out separately, so you could use higher current at lower supply voltages.

National did some *weird* stuff in 1988--they came out with about 20 new

*hybrid* designs, like the LH4009 buffer. Of course, those lasted about 2 years and went the way of the dodo. I still have some.

Cheers,

Phil Hobbs

ah, the JFETs are the dual LSK389 , from Linear Systems,

no as cheap as Joerg would like, but a nice dual anyway.

Thanks , Jure Z.

But snow is slippery and (often) soft.

A couple of years ago I was skiing backwards pretty fast and hit a bump. My tips dug in and I went down on my butt, hard, in milliseconds. I bruised my butt, which I expected, but there must have been a shock wave or something, because I had a mean-looking matching bruise on the opposite side, on my belly. The shock wave apparently didn't hit any vital organs.

John

BTW, that brings up an old friend: What happened to the 2N4417? Is it still for sale somewhere or did I miss the obituary?

--
Regards, Joerg

http://www.analogconsultants.com/

They also did some not-so-nice stuff. Brought LH0063 and 0033 buffers to market, excellent parts, used by ATE folks all around the globe, then sent out the funeral notice. Now there is the occasional fist fight among obsolete-parts dealers if a stash shows up somewhere.

--
Regards, Joerg

http://www.analogconsultants.com/

Lawrence, I've got two pages for it in the 1988 databook here. But it's very little data because they called it "advanced information". Those parts must have kicked the bucket almost before hitting the market because there is no mention at all in the 1995 databook. IOW maybe there never was a publicly released datasheet. Maybe Bob Pease has one ;-)

Do you want those two pages? If so, do I just leave the "y" out of your email address?

--
Regards, Joerg

http://www.analogconsultants.com/

Thanks, Joerg - Take out all the lowercase to email, and yes, I would appreciate those. I _may_ have more data on them in a box somewhere, but certainly my OpAmp book which is to hand is the 1995 version. The parts themselves appear to be from the 40th and 42nd week of 1989, in cute shiny metal can (CIH) packages.

Got only one LH0063 in the hoard, unfortunately. Should I put it on *B*y and retire from the proceeds? Somehow I doubt it would come to much... Looks like one vendor is flogging 8 of them at $60 each.

I have to agree that it was bizarre to bring out such nice, useful stuff and then axe them so quickly.

--
Cats, coffee, chocolate...vices to live by