C33716 Transistor Identification—Is It the Same as BC337 or a Different Component?

Hi -I must have known once, when I bought them, but now I'm trying to tidy and organise (yes, stop sniggering!), and I've forgotten.
A datasheet search keeps taking me to a BC337. Is that right? Or is it something else?Thank-you!
Graham

I did a google search for "C33716" and the following came up:
https://www.mouser.com/Semiconductors/Discret...lar-Transistors-BJT/_/N-5gcb?keyword=C33716So it appears that they are NPN transistors and that they are still in production. You should be able to get the data sheet through Mouser or directly from one of the manufacturers.

Yes, thanks, but that takes you to a page with buttons: Products (6) and Datasheets (3), both of which take you to items beginning with BC337.So I still don't know if that's actually what it is, or if that's an anomaly of the search engine's trying for the nearest fit.

You're right it's not entirely clear. Do you have a transistor tester you can use to check it out?

HiFollowing on from Elizabeth, if you have an Atlas DCA55 or the like you can obtain the characteristics and compare to potential datasheets.I'm assuming you have enough of these to make it worth your while finding out what they are, so if you get no luck in your search and if it helps, you could post one to me (UK) and I will give you the results from an Atlas. PM for details if that is of interest.Regards

The data sheets are not very clear, but I think the following is correct.On the "ON Semiconductor" data sheet look under "Part Number" and " Top Marking" you will see some marked BC33716 and Bc33725 and BC33740.  Then look on the next page of the data sheet under  "hFE Classification". There are 3 ranges of hFE  they are identified by adding  16, 25, or 40 to the end of the BC337 part number to indicate the hFE range. The hFE for your BC33716 would be 100-250. 

As I recall, A BC337-16 (usually marked as per Graham's sample BC33716) is a BC337 with an HFE (current gain) around 160.  You also get BC33725 with an HFE around 250 and a BC33740 with an HFE around 400.  These values are confirmed by Elizabeth's datasheet, although it does not give the typical values, but they are in the middle of the ranges given.  A transistor marked simply BC337 could have an HFE anywhere in the range - 100 to 630.Elizabeth - I feel another one of your datasheet series coming on ??

Graham I should have mentioned this in my post above, but here goes.... When I was a young man, our goto small signal transistors were the BC108 series.  These had very similar gain markings, but you'd find transistors marked BC108A, BC108B, BC108C or just plain BC108.  The A,B,C were gain indicators much like the 16,25,40 that you get on the BC337 that you found.  The BC108 datasheet is here, and on page 4 you can see the gain ranges represented by the letters.I think the A,B,C suffixes are a better way of doing it, but that's progress for you!The BC 107/8/9/ series were in the cute (but more expensive) metal top-hat TO-18 package.  The newer BC547-8-9 (and your BC337 and many other variants) are more or less the same transistors in the much cheaper TO-92 plastic package.The excellent Elektor magazine took advantage of the similarity between these transistors and used to specify TUP or TUN transistors in their projects, for Transistor, Universal, Pnp or Npn.  They also specified diodes as DUG or DUS (Diode, Universal, Germanium / Silicon.  They used to print a page of TUPTUNDUGDUS in their issues and you can still find it on the web here.  It's a useful reference to have around.Oh...guess what...the BC337 is not on there.... not sure why...might be not within the minimum specs, or maybe only came out later.  Don't have tijme to investigate now, I am at work

Graham at the risk of boring you, I went through a very similar search in my teens when I was getting interested in electronics.  I have always been an inveterate stripper of old PC boards for parts and as a teenager that was my main source of parts.  I documented this here.  The 2N2926 transistors that I got of the boards my dad brought home were not marked as such, but I eventually identified them.  They identified the gain ranges not by a number or letter, but a dot of paint.  The original datasheet link I gave in the article no longer works, but I found a catalogue scan here that has them and I reproduce below the table of the gain ranges vs colours:
They reckon that up to 6% of the devices were in the brown range but most of the ones I got seemed to be brown ones.  I guess the manufacturer got those ones dirt cheap   I did get a few of the other colours and guarded the green ones for important projects.Anyway, take comfort in the fact that many others have gone through the same travails before you

Thank-you very much, all, for your thoughts. So are we assuming that the prefix should be "BC", but the "B" is missed off for some reason?David - no chance of boring me! Thanks for your time and info.Chip - I've got 8 of them. Not a large number, but there's only so much room in the Misc bin! If you could identify their characteristics that would be useful as well as interesting. I'll pm if I may, as you suggested.Cheerrs, GrahamPS: It's not important, but I was idly wondering what the "BC" stands for in the BCxxx range of transistors. Anyone happen to know?

Graham...thanks for the reply, it's great to get feedback and it's good we have been of help.> ...but I was idly wondering what the "BC" stands for in the BCxxx range of transistors..."This is what is known as a "Can of worms"...   There are quite a few transistor numbering codes.  European manufacturers use the Pro-Electron system, a portion of which I reproduce below:
So you can see that a transistor labelled "BCxxx" will be a Silicon Audio Frequency Low Power Transistor. There are other systems as well.  American semiconductors use the JEDEC system, where 1 is a diode, 2 is a transistor and 3 are four-lead devices...usually obscure double-gate mosfets and the like. The letter is followed by N and the number.  So a 1N914 is a diode and the venerable 2N3055 is a transistor. I prefer the Pro-Electron system as it gives you more precise data about the type of device you're dealing with.  For example an AC126 is a Germanium audio transistor, and an AD161 is a Germanium power transistor.  I came across both a lot in my younger days.There are other systems as well, for example the Japanese JIS, which is kinda similar to the Pro-electron in that it gives a fairly precise indication of what kind of device you have:Digits are 1 for diodes, 2 for transistors,
and so forth. 2SA: PNP HF transistor 2SB: PNP AF transistor 2SC: NPN HF transistor 2SD: NPN AF transistor SE: 2SJ: P-channel FET











2SK: N-channel FET 
The other thing you have to get used to is manufacturers leaving letters and other things off, as you found with your C33716, which is actually a BC337-16.  Japanese FETS will often have just Kxxx on them. But to complicate matters some manufacturers go it alone and have their own proprietary numbering, Motorola for example made transistors with numbers like MJ, MPS, etc.  So it's one of those things that you acquire a "feel" for over many years.  Google is your friend here, most times you can put a number in and get a datasheet unless it's a really weird proprietary device.  If you get used to putting in the missing letters it helps you locate a datasheet a bit faster....
Here are some links that might be worth looking at:Pro-Electron and JEDECA good one covering most systemsHope this helps.  Cheers / David


 

That's very excellent again, thank-you!
(It's the simplest questions..! ) w

Graham, I just scratched the surface above, as I said - can of worms....There used to be an excellent book called Towers International Transistor Selector (I always use the acronym which is not as valuable as it used to be, but you can pick them up off ebay in good condition for a few dollars.  Data and pinouts on thousands of devices....And it's a pleasure, especially when we get some appreciation!