I want a transistor

Nov 19, 2007 21 Replies

In the search for a fast, high voltage transistor, I've found the perfect type: 2SC4679. Problem: it only exists in datasheets. The usual suspects don't sell it or its equivalents.


-- Deep Fryer: A very philosophical monk. Website @

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You didn't mention: How fast? How high in voltage? Since Toshiba doesn't seem to find it that transistor may be gone. HV plus fast usually means video transistor, the ones that drive the CRT. But since CRTs are going the path of the dinosaurs now ...

Regards, Joerg http://www.analogconsultants.com/

Fast? High voltage? Could you please be a little less specific?

John

On a sunny day (Mon, 19 Nov 2007 13:23:46 -0600) it happened "Tim Williams" wrote in :

How many volts do you need?

That is a nice one, 300V, 100mA, 240MHz, 3pF, 8W. Nice.

Entering the p/n into Google gave this:

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They claim to have 1233 of them.

Bob

Enter the part number in Mouser and you get a relay :) LOL

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Boris Mohar

Geez, John, he _did_ reference a data sheet.

Try this:

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JF

Aye, Captain! And a very FAST relay it is, too!!!

Dave M MasonDG44 at comcast dot net (Just substitute the appropriate characters in the address) "In theory, there isn\'t any difference between theory and practice. In practice, there is." - Yogi Berra

250 million switch closures per second! Wow! But it's only rated for four seconds continuous use! :'(

Or something like that...

Tim

-- Deep Fryer: A very philosophical monk. Website @

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Bleh...at a minimum order of approximately 10,000 or something like that?

I'm not Joerg...

Tim

-- Deep Fryer: A very philosophical monk. Website @

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Refs I saw for it state something like HDTV chroma/video output, so it can't be *too* dead.

The Toshiba datasheet I found for it is dated 2001. How often do they rotate their parts numbers?

Why is it that, for all the billions of transistor types made by a hundred countries around the world, 3 x 10^5 are 30V, 100mA NPN general purpose/switching transistors, and about four are the type I actually want at any given moment?

Tim

-- Deep Fryer: A very philosophical monk. Website @

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You need to start thinking outside-the-box, Tim. Sell the other 9,998 on Ebay.

You're welcome, in advance.

Bob

Well, one of the last HDTV series is the Samsung SlimFit 30". A very nice set. I almost fell for it but it's a tad too small and very heavy so even I as a rather conservative shopper will probably head out this week and buy a Vizio 37" at Costco. So there you go, the market for those transistors just shrank by another three devices.

I don't think they rotate. It's just that markets vanish. 20 years ago you could buy CRT driver transistors at almost any electronics place and TV repair shops. No more.

Tell me about it. I guess we are in the same boat, just in other market segments. I was especially sad when FET arrays such as the SD5400 began their trek to lalaland.

Regards, Joerg http://www.analogconsultants.com/

Yup. And I recently found some interesting compementary pairs that might be useful:

Toshiba:

2SC5171 180V, 2A, 20W, 16pF, 200MHz 2SA1930 180V, 2A, 20W, 26pF, 200MHz

Want really fast? Try those Philips/NXP BFQ232,232A NPN 100V/115V, 300mA, 1.4GHz, 2pF, 3W-TO126 BFQ252,252A PNP 100V/115V, 300mA, 1.3GHz, 2.5pF, 3W-TO126

Thanks, Fred.

Whoa, 2A? Is that peak (low average dissipation, possibly TO-92 -- emitter follower stock) or continuous? I'm not interested in burning more than

100mA quiescent here...

Ayup, I have a few like that -- BFQ225 is 100V, ~1GHz, 100mA, TO-202 package. The monitor boards came with a PH2369 at the bottom of the cascode and a complementary pair of BFQ221/241 emitter followering into the CRT grid. :-)

Not enough voltage though.

Tim

-- Deep Fryer: A very philosophical monk. Website @

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John Fields snipped-for-privacy@austininstruments.com posted to sci.electronics.design:

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What a piece of garbage site. Where is the datasheet? PS NO cookies.

On a sunny day (Thu, 22 Nov 2007 22:01:10 -0800) it happened JosephKK wrote in :

It is a very good site, does your mouse have buttons?

Jan Panteltje snipped-for-privacy@yahoo.com posted to sci.electronics.design:

Got to tired of can't do anything without cookies.

On a sunny day (Fri, 23 Nov 2007 20:32:54 GMT) it happened JosephKK wrote in :

You mean you have them cookies disabled? hardly any site is cooky free thse days no? Cookies are not dangerous, they are just little flufs on your harddisk, not executable as far as I know.

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