CD or DVD with all datasheets in the world?

I have over 30,000 datasheets taking about 15G of space. They were all individually scanned or downloaded and are carefully named and organized in company folders. This was done over a period of many years, while I was evaluating parts for designs and researching the AoE recommended-part tables. I'm sure this is only a tiny fraction of "all the datasheets in the world." There are several websites that aspire to that claim, and they must have far more than 10x as many datasheets as me. At least I have _most_ of the datasheets I need for my daily work. :-)

--
 Thanks,
    - Win

I see ChipDocs credits PartMiner FreeTradeZone with 12 million "datasheet records," and PartMiner says their users can access "35 million electronic components from over 1,900 manufacturers" so that swamps my measly 30,000 datasheets. But they enter into their database and count all 50 zener-diode types appearing on a single datasheet, as 50 parts, etc., whereas I count it as one. I doubt they have 1,000x more than me, but whatever, it's a lot.

--
 Thanks,
    - Win

Is there some place that could cheaply sell me media with a large selection of datasheets. Thanks

i

I have the 2sb737 here at home, I may have the 2sk240 at work.

--
 Thanks,
    - Win

Just curious, how many do you have and where did you get them? (unless you simply downloaded the ones that you needed). I realize that datasheets need quite a bit of disk space. One or 20 DVDs, does not matter too much to me.

I want to build some sort of a datasheet explorer website in some nice way, sort of like my site cooldictionary.com etc.

i

On 12/12/2005 the venerable Fred Bartoli etched in runes:

has every 2SB73x *except* for 2SB737. I didn't look for 2SK240

--
John B

Hi Win,

I guess you must then have the 2SB737 I couldn't find anywhere. I'm also searching the 2SK240 as well but you don't mention it in AoE so... :-)

--
Thanks,
Fred.

The 2sb737 is a Rohm PNP with an r_bb' of 2 ohms, typical, and it's the complement to their 2sd786 NPN with r_bb' of 4 ohms. Both transistors are claimed to deliver e_n = 0.55nV at 10Hz if operated with Ic = 10mA, and their plots show 0.4nV at 1kHz.

The voltage-noise density, e_n, is thought to originate from the transistor's collector shot noise against half its r_e, plus a term from the base spreading resistance, r_bb'. Since r_e goes down with Ic, and is only 2.5 ohms at 10mA, it's desirable to have a very low r_bb' - in the same 2 to 4 ohm territory. In the above 10mA region r_bb' becomes a dominant noise source. The Johnson noise from 4 ohms is 0.256nV, so we wouldn't want r_bb' much above 4 ohms to enjoy a nice low e_n near 0.5nV.

I have a healthy supply of 2sd786 transistors, which I got from an s.e.d. denizen, who had lots more, IIRC. Mine do measure in the 0.5nV territory. I've never crossed paths with a 2sb737.

I'm not sure how they measure r_bb' - it can't be through e_n, because the measured e_n is too high for the Johnson-noise formula with r_bb' and 0.5 r_e as the only sources.

As for close equivalents, Toshiba's 2sc3329 NPN and 2sa1316 PNP transistors claim to have r_bb' = 2-ohms (if you can get 'em).

And yes, the Hitachi (Renesas) 2sa1083 to 2sa1085 and 2sc2545 to 2sc2547 families claim to have 0.5nV noise at 10mA and 1kHz. They don't mention r_bb', but it has to be very low. I wonder if these are available somewhere.

--
 Thanks,
    - Win

2SB737, are rare as hens teeth. I know of one company that has a few thousand, for internal use only.

Any close equivalents, 2SA1085 maybe?

martin

We are adding a cross reference database to the datasheetarchive soon. Around 600,000 parts.

I looked up 2SB737 and it returned these as similar parts: BC416,

2SD786, 2N5373, 2N3859A, BC184. I'm not sure how accurate this information is. We are still validating the database.

The extra data will go live once we've validated it.

I use the 2SA1084 regularly. They do seem to be around. Our Asian sub-contractors source them for us. That device is widely used in pro-audio mic pre-amps.

The 2SB737 is a tiny bit quieter but beware the large Cob. I've measured THD caused by it's modulation by the signal at higher audio frequencies. Rohm no longer make it seems btw. It was originally designed as an amplifier for moving coil magnetic cartridge pick ups. I know an outfit who have their own little 'stockpile' of them.

No idea if the 2SA1316 is still available.

Graham

I'm sure we'll be doing that. I may go ahead for the 2nd ed.

--
 Thanks,
    - Win

Go and find them!! I'll trade you some 2sd786 for some 2sb737.

--
 Thanks,
    - Win

It is also the quality of the data sheet.

The SB737 has nice plots of noise against source resistance and collector current and at various frequencies. The average data sheet will just say x dB noise and very little other information. There is also the problem that several manufacturers would make, say a BC184, and they would not really be the same noisewise.

On some of the proaudio forums they often say dont use xxx transistor from company A but only from company B. The 2N4403, for some reason, sticks in my mind

I dont know haw a datasheet archiver could cope with this. But usually I go straight to the source, rather than a third party

martin

On 12 Dec 2005 13:53:55 -0800 in sci.electronics.design, Winfield Hill wrote,

I would be happy with just the AoE recommended parts datasheets all in one place (on your web page?)

I used to use the 2SD786 in a super-low-noise discrete preamp I manufactured for use with LN2-cooled HgCdTe IR detectors for low-frequency operation. My customer said that was the quietest preamp he'd ever seen. I still have a few 786s hanging around.

Around 15 years ago I bought 500 2SB737s from the local disti, it was the same price as if I bought 100. Gotta find them some day...

How would the Zetex ztx788/ztx789 compare (WRT noise, not other features) with the above type transistors? They aren't speced for low noise, but appear to have most of the appropriate attributes of a low noise part (also the ztx688/ztx689 for NPN.) Their biggest problems might be the high capacitance and associated dynamic effects. Zetex even suggests their use for low noise, but since I don't have any of the cool Japanese low noise parts, I don't have an easy way to directly compare...

John

Some brokers show stock on the '737:

--
newell

OK, I'll root around a bit this weekend, I have a general idea where they might be hiding. Do you still have my biz card? I gave it to you around a year ago when Jim T was in town.

Steve