BC550C/BC560C brand/source/replacement

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Samuel Groner

Well-known member
Joined
Aug 19, 2004
Messages
2,940
Location
Zürich, Switzerland
Hi

For some newer projects I need TO-92 complementary transistors with higher hfe than my beloved 2N4401/2N4403 and BC550C/BC560C seem to fit. What brand are you using? ON semi has the best specs regarding capacity and fT, so I think I go with these.

Can someone recommend a source for them? The ones I found are very expensive.

Or is there a different transistor I should consider? I spent a few hours browsing the Toshiba and Renesas sites and found 2SA1015/2SC185 as well as 2SA1190/2SC2855. Both seem to spec worse regarding fT, so I'm still with the BC parts if you don't proof me otherwise.

Thanks!
Samuel

BTW, did you see the 2N3904 fT spec from Renesas? 0.5 GHz...
 
i use the ON bc550/560 frequently without any problems!

i get them from Mouser here in the USA, not sure where you can get them in Europe..

:thumb:
 
Hey, you are right! what the.. i just used the last of the parts i got from mouser, but i bought them sometime last year in a large bag.. maybe they don't carry them anymore?

strange.. maybe i just need to get drunk?

:guinness:
 
[quote author="Samuel Groner"]
Can someone recommend a source for them? The ones I found are very expensive.
[/quote]

You mean the ON ones or in general?

BC550/560 are about the cheapest transistors I can get around here, but nobody states the manufacurer. You get whatever they have. They're Philips mostly; I don't think I ever had ON ones. As you probably know Rbb is not particularly low on the BC550/560. I wouldn't use them for a microphone input, although I've seen them used as such in commercial products.
 
That's interesting about the higher Ft for Renesas. Most of the time there won't be too much effect due to that though unless it is really low. Look carefully at the operating point for this performance too---it's likely at a rather high combination of voltage and current.

I have designed with >1GHz parts in linear mid-freq amps in an attempt to improve performance. You can get there, but the topologies get elaborate in order to have good d.c./low frequency performance, and the geometry of the layout gets so critical for reducing stray L and C and avoiding oscillation.

I tend to go with 1015/1815 in the highest beta codes available for through-hole work unless there is a compelling reason otherwise.
 
Thanks for the answers and suggestions! I found a supplier in switzerland - 25k min order, who wants a few? :?

Rossi, even other brands seem to be expensive here, sometimes up to 0.70 CHF (0.50$).

KSC1845/KSA992 look interesting, a bit low fT though - for my taste.

Brad, do you have a source for the L-graded 1015/1815? These would be interesting for some things.

Samuel
 
Samuel, try http://www.reichelt.de/
They're cheap and reliable. BC550/560 are 0.03/0.04 Euro.
 
[quote author="Samuel Groner"] Brad, do you have a source for the L-graded 1015/1815? These would be interesting for some things.

Samuel[/quote]

Note (for others since you I think understand this already) that there is an "L" part, supposedly "low noise", for each number, that is not the same as the beta code, which is an additional suffix. I have never found anyone stocking these, but I have also never found a high noise plain 1815 or 1015.

A friend got the 2SC1815BL and the 2SA1015GR from Chips T*chnology Circuits in NJ. The 1015's don't go any higher than GR unfortunately.
 
Peter and Rossi, thanks for those links.

BTW, I found the SS9014/SS9015 pair which looks like the prototype for the perfect high-hfe audio transistor; unfortunately the D grade seems to be discontinued (Mouser says so).

Samuel
 
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