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Currently says: The BC548 and BC549, and their PNP counterparts (BC558 and BC559) can be used in circuits where voltages reach no more than 30 Volts, limited mainly by their VCEO rating. The VCBO rating refers to the maximum voltage between collector and base with the emitter open-circuit (not typical operation),
This is wrong. Vcbo is the relevant voltage so long as you ensure the b-e junction doesn't get forward biased by stray currents leaking across the c-b junction. Nick Hill ( talk) 13:07, 26 July 2015 (UTC)
It isn't that emphasizing Vceo is so much "wrong" as the cautious rating. Unless you know the external resistance in the base-emitter circuit is going to be low enough the safe way to go is to abide by the Vceo rating. There is a curve - although not always published for each transistor - relating the Vce breakdown rating as a function of the R between base and emitter... and the resistance needed to bring the Vcbr rating up to the Vcbo rating can be surprisingly low for small-signal transistors. Most amplifier circuits shun such low value resistors in the bias circuit because it cripples the current gain. There are other factors to complicate things, but the text in the article mentioned above ("...limited mainly by their VCEO rating...") is gone now, and fair enough... such discussions complicate, and are not entirely relevant to, this particular article, but there should be something more on this question of which breakdown voltage to go by... perhaps more is needed in the Breakdown Voltage article?? It hardly says anything at the moment. Maitchy ( talk) 02:34, 28 March 2017 (UTC)
The series sections should really be separate articles, perhaps with this redirecting to the BC series article.
65.93.12.101 ( talk) 03:52, 27 March 2011 (UTC)
A merge was suggested at the wikiproject, that BC548 be merged to 2N3904. This should obviously involve BC548 specific material. The series/family material would probably be better in a different article. 65.93.12.101 ( talk) 05:53, 28 March 2011 (UTC)
Hello everybody, I am the creator of this page originally and live in Australia. I created the page after reading the 2N2222 page. I have seen many North American Electronics publications (such as the ARRL Handbook) and the constant references to 2N2222s and 2N2907s etc. These JEDEC devices give a typically North American view, but this is not the only view that there is! In other Geographical Realms, other similar devices are more commonly available and used. I agree with Andy Dingely, whom is probably in the U.K. that the BC family of devices deserve a page of their own, distinct from the North American pages featuring JEDEC devices. I propose yet another page....has anyone ever pulled apart a piece of Asian Consumer Electronics and found dozens of 2SC1815s, well these are yet another manifestation of the BC548 and 2N3904. I have been to Viet Nam and there, in the Yersin electronics market in Ho Chi Minh City, (Sai Gon), there were no BC548s or 2N3904s to be seen or even known about, but 2SC1815s and their compliment, the 2SA1015, and be bought in bags of hundreds at a very cheap price and can be substituted for the other realm devces in most applications by simply "dogging the legs about" because the collector lead is in the middle. So this page serves to introduce those new to electronics, and dare I say, some too poor to purchase devices new and must resort to wrecking them out of discarded gear, a hand into electronics by realizing that the 2SC1815 they scavanged from an old Getto blaster on a rubbish heap is actually nearly the same as that 2N3904 in the window of the local electronics dealer.
I hope to also use this page, and others like it, to share my considerable knowledge as an electronics technician for thirty years with a hopefully curious enough up and coming generation, because i won't be much good to anyone once I go up the Crematorium Chimney.
Globe Collector ( talk) 11:27, 16 April 2011 (UTC)
I have compared data sheets for both BC54x and 2N3904. They appear to be quite different devices. BC54x would apparently be a superior replacement for the 2N3904 where gain linearity will improve circuit performance. Obviously, BC548 would not substitute a 2N3904 if the circuit needs to switch more than 30v. The article defines parameters (incidentally, erroneously) when the parameters are equally valid over thousands of different component part numbers. The article appears to be a verbose version of what can tersely be included in a table of common BJTs along with their key parameters and notes.I recommend deleting all pages such as 2N3904 2N2222 BC108 family then link them all to one page containing a table.
If we wanted to have information on 15 products, differing in only details, would it be better to have 15 pages, with most of the information duplicated across all those pages with edits here and edits there, some being good, others introducing errors, or would it be better to summarise what the devices do in general, describe the salient parameters, then list the devices showing the salient parameters?
I propose a table along the lines of this. This way, a hobbyist can make their own mind up about the cross compatibility, and all the information is easily accessible. Article should show a diagram of a TO18, a TO92 with pin numbering and explain Ic Vcb Vce Hfe Ft .
I suppose we need to approach this from the perspective of what would someone visiting a page or array of pages, most useful. If it is about the history of the companies involved, then we would start with the company, the designers, the processes then the parts themselves.
If we are talking about Transistors from a functional and usefulness perspective, we would generalise in an order similar to most catalogues: 1) It's a transistor 2) it's bipolar 3) Silicon 4) Small signal Ptot <=1W 5) Part numbers, salient parameters and what they would be most useful for.
Couldn't all relevant information about small signal silicon bipolar transistors live on one page, and wouldn't this make sense? Indeed, if the information isn't extremely detailed, see how it grows, have a page on silicon bipolar transistors with sections going into details of examples of small, medium and high power. A table for each category with perhaps 20-30 examples would be a great cross reference and information resource. It doesn't seem to make sense to spread it over a large number of pages as the same information will tend to be repeated time and again. Nick Hill ( talk) 19:01, 26 July 2015 (UTC)
Typical values. Refer to specific manufacturer's data sheets. Case numbering looking from below. TO18 pin 1 next to tab, counting clockwise. TO92 flat facing up, 1 to the left.
Part Number |
Type | Ic (ma) | Vcb | Vce | Hfe | Ft | Ptot (Mw) | Pin Layout 1 2 3 |
Case | Notes |
---|---|---|---|---|---|---|---|---|---|---|
BC546 | NPN | 100 | 80 | 65 | 100-800 | 300 | 500 | C B E | TO92 | Linear gain [1] |
BC556 | PNP | 100 | 80 | 65 | 100-800 | 150 | 500 | C B E | TO92 | Linear gain [2] |
BC107 | NPN | 100 | 50 | 45 | 100-800 | 150 | 600 | E B C | TO18 | Replaced with BC547 [3] |
BC547 | NPN | 100 | 50 | 45 | 100-800 | 300 | 500 | C B E | TO92 | Linear gain [1] |
BC557 | PNP | 100 | 50 | 45 | 100-800 | 150 | 500 | C B E | TO92 | Linear gain [2] |
BC108 | NPN | 100 | 30 | 25 | 100-800 | 150 | 600 | E B C | TO18 | Replaced with BC548 [3] |
BC548 | NPN | 100 | 30 | 30 | 100-800 | 300 | 500 | C B E | TO92 | Linear gain, Low noise [1] |
BC558 | PNP | 100 | 30 | 30 | 100-800 | 150 | 500 | C B E | TO92 | Linear gain, Low noise [2] |
BC109 | NPN | 100 | 30 | 25 | 100-800 | 150 | 600 | E B C | TO18 | Lower noise version of BC108 Replaced with BC549 [3] |
BC549 | NPN | 100 | 30 | 30 | 100-800 | 300 | 500 | C B E | TO92 | Linear gain, Low noise [1] |
BC559 | PNP | 100 | 30 | 30 | 100-800 | 150 | 500 | C B E | TO92 | Linear gain, Low noise [2] |
BC550 | NPN | 100 | 50 | 45 | 100-800 | 300 | 500 | C B E | TO92 | Linear gain, Low noise [1] |
BC560 | PNP | 100 | 50 | 45 | 100-800 | 150 | 500 | C B E | TO92 | Linear gain, Low noise [2] |
2N3904 | NPN | 200 | 60 | 40 | 30-300 | 270 | 625 | E B C | TO92 | Non-linear gain [4] |
2N3906 | PNP | 200 | 60 | 40 | 30-300 | 250 | 625 | E B C | TO92 | Non-linear gain [5] |
2N2222A P2N2222A |
NPN | 600 | 75 | 40 | 35-300 | 250 | 500 | E B C C B E |
TO18 TO92 |
Non-linear gain [6] |
Nick Hill ( talk) 19:47, 26 July 2015 (UTC)
References
Why do Pro Electron devices come in JEDEC packages? Surely they would at least have come up with their own metric packages. -- Wtshymanski ( talk) 03:27, 4 April 2011 (UTC)
This part number is not notable and is not a suitable topic for an encyclopedia article. Even history books about the semiconductor business don't spend any time on individual part numbers, because they aren't important to understanding semiconductors and thier roles. -- Wtshymanski ( talk) 13:38, 5 April 2011 (UTC)
The BC548, and the family it belongs to, are VERY notable in Europe and places like Australia/New Zealand, but some of the comments on this page are understandable given the way that some types were famous in half of the world but hardly known in the other half. There are many references that could (and should) be brought in to show the significance of the family that can be described by the neat table:
Case | Polarity | 80Vcbo | 50Vcbo | 30Vcbo | Low-Noise 30V | Low-Noise 50V |
---|---|---|---|---|---|---|
TO-18 | NPN | BC107 | BC108 | BC109 | ||
PNP | BC177 | BC178 | BC179 | |||
Lockfit | NPN | BC147 | BC148 | BC149 | ||
PNP | BC157 | BC158 | BC159 | |||
TO92B (e-c-b) |
NPN | BC167 | BC168 | BC169 | ||
PNP | BC257 | BC258 | BC259 | |||
TO92F (c-b-e) 350mW |
NPN | BC237 | BC238 | BC239 | ||
PNP | BC307 | BC308 | BC309 | |||
TO92A (e-b-c) |
NPN | BC317 | BC318 | BC319 | ||
PNP | BC320 | BC321 | BC322 | |||
TO92F (c-b-e) 625mW |
NPN | BC546 | BC547 | BC548 | BC549 | BC550 |
PNP | BC556 | BC557 | BC558 | BC559 | BC560 | |
SMD | NPN | BC846 | BC847 | BC848 | BC849 | BC850 |
PNP | BC856 | BC857 | BC858 | BC859 | BC860 |
(see also:
[1] for a neat summary of some of the family).
One typical reference is: [2], another is a news item in Practical Wireless (I think it was) when the grandparents of the family were introduced around 1966 (I don't have that reference to hand, but could find it). The fact is that the BC107/8/9 family became the most common types to be specified in magazine articles and so on for many years after the days of the OC71 and before the plastic versions BC547/8/9 took over. The Australian Philips "MiniWatt" article I just mentioned begins with a statement saying how important the BC107/8/9 transistors were.
Where the criticisms on this page have something worth noting is that there is a lack of encyclopedic information, and this could and should be expanded. The article should show:
I certainly think the BC548-family article is needed, and trying to cover this only in something spanning all BCxxx types would be a mistake - it is too notable a group of transistors. Maitchy ( talk) 00:17, 17 March 2014 (UTC)
Most of this article isn't about its putative subject. Aside from the parts list data sheet numbers, we still haven't been told anything about *this* transistor type. What company first registered it, and when? Is it still made? Are as many being made now as in, oh, say, 1978? Do we know anything notable about this transistor at all? -- Wtshymanski ( talk) 18:48, 17 April 2011 (UTC)
What is the purpose of this page? So far I see
If people want datasheet type content, there's a vast amount of it available, and someone could write thousands of new pages. 82.31.207.100 ( talk) 14:48, 24 July 2011 (UTC)
I came to this article because I am doing up a circuit that uses the BC548, and it isn't as common in North America as it is in Europe and the UK. So I thought: I'll read up!
The article, before I went to work on it with a few dozen or more edits, was tagged as Refimprove and "incomprehensible", or "too technical". I have to agree. It was a fairly large assortment of very technical info. I made quite a large number of edits based on the following:
In any case, I think it now reads well. It brings out the main points:
For more info, see datasheet! HappyValleyEditor ( talk) 02:36, 8 March 2016 (UTC)
![]() | This page was proposed for deletion by an editor in the past. |
![]() | This article was nominated for deletion on 26 March 2011. The result of the discussion was keep. |
![]() | This article is rated Stub-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | ||||||||||
|
Currently says: The BC548 and BC549, and their PNP counterparts (BC558 and BC559) can be used in circuits where voltages reach no more than 30 Volts, limited mainly by their VCEO rating. The VCBO rating refers to the maximum voltage between collector and base with the emitter open-circuit (not typical operation),
This is wrong. Vcbo is the relevant voltage so long as you ensure the b-e junction doesn't get forward biased by stray currents leaking across the c-b junction. Nick Hill ( talk) 13:07, 26 July 2015 (UTC)
It isn't that emphasizing Vceo is so much "wrong" as the cautious rating. Unless you know the external resistance in the base-emitter circuit is going to be low enough the safe way to go is to abide by the Vceo rating. There is a curve - although not always published for each transistor - relating the Vce breakdown rating as a function of the R between base and emitter... and the resistance needed to bring the Vcbr rating up to the Vcbo rating can be surprisingly low for small-signal transistors. Most amplifier circuits shun such low value resistors in the bias circuit because it cripples the current gain. There are other factors to complicate things, but the text in the article mentioned above ("...limited mainly by their VCEO rating...") is gone now, and fair enough... such discussions complicate, and are not entirely relevant to, this particular article, but there should be something more on this question of which breakdown voltage to go by... perhaps more is needed in the Breakdown Voltage article?? It hardly says anything at the moment. Maitchy ( talk) 02:34, 28 March 2017 (UTC)
The series sections should really be separate articles, perhaps with this redirecting to the BC series article.
65.93.12.101 ( talk) 03:52, 27 March 2011 (UTC)
A merge was suggested at the wikiproject, that BC548 be merged to 2N3904. This should obviously involve BC548 specific material. The series/family material would probably be better in a different article. 65.93.12.101 ( talk) 05:53, 28 March 2011 (UTC)
Hello everybody, I am the creator of this page originally and live in Australia. I created the page after reading the 2N2222 page. I have seen many North American Electronics publications (such as the ARRL Handbook) and the constant references to 2N2222s and 2N2907s etc. These JEDEC devices give a typically North American view, but this is not the only view that there is! In other Geographical Realms, other similar devices are more commonly available and used. I agree with Andy Dingely, whom is probably in the U.K. that the BC family of devices deserve a page of their own, distinct from the North American pages featuring JEDEC devices. I propose yet another page....has anyone ever pulled apart a piece of Asian Consumer Electronics and found dozens of 2SC1815s, well these are yet another manifestation of the BC548 and 2N3904. I have been to Viet Nam and there, in the Yersin electronics market in Ho Chi Minh City, (Sai Gon), there were no BC548s or 2N3904s to be seen or even known about, but 2SC1815s and their compliment, the 2SA1015, and be bought in bags of hundreds at a very cheap price and can be substituted for the other realm devces in most applications by simply "dogging the legs about" because the collector lead is in the middle. So this page serves to introduce those new to electronics, and dare I say, some too poor to purchase devices new and must resort to wrecking them out of discarded gear, a hand into electronics by realizing that the 2SC1815 they scavanged from an old Getto blaster on a rubbish heap is actually nearly the same as that 2N3904 in the window of the local electronics dealer.
I hope to also use this page, and others like it, to share my considerable knowledge as an electronics technician for thirty years with a hopefully curious enough up and coming generation, because i won't be much good to anyone once I go up the Crematorium Chimney.
Globe Collector ( talk) 11:27, 16 April 2011 (UTC)
I have compared data sheets for both BC54x and 2N3904. They appear to be quite different devices. BC54x would apparently be a superior replacement for the 2N3904 where gain linearity will improve circuit performance. Obviously, BC548 would not substitute a 2N3904 if the circuit needs to switch more than 30v. The article defines parameters (incidentally, erroneously) when the parameters are equally valid over thousands of different component part numbers. The article appears to be a verbose version of what can tersely be included in a table of common BJTs along with their key parameters and notes.I recommend deleting all pages such as 2N3904 2N2222 BC108 family then link them all to one page containing a table.
If we wanted to have information on 15 products, differing in only details, would it be better to have 15 pages, with most of the information duplicated across all those pages with edits here and edits there, some being good, others introducing errors, or would it be better to summarise what the devices do in general, describe the salient parameters, then list the devices showing the salient parameters?
I propose a table along the lines of this. This way, a hobbyist can make their own mind up about the cross compatibility, and all the information is easily accessible. Article should show a diagram of a TO18, a TO92 with pin numbering and explain Ic Vcb Vce Hfe Ft .
I suppose we need to approach this from the perspective of what would someone visiting a page or array of pages, most useful. If it is about the history of the companies involved, then we would start with the company, the designers, the processes then the parts themselves.
If we are talking about Transistors from a functional and usefulness perspective, we would generalise in an order similar to most catalogues: 1) It's a transistor 2) it's bipolar 3) Silicon 4) Small signal Ptot <=1W 5) Part numbers, salient parameters and what they would be most useful for.
Couldn't all relevant information about small signal silicon bipolar transistors live on one page, and wouldn't this make sense? Indeed, if the information isn't extremely detailed, see how it grows, have a page on silicon bipolar transistors with sections going into details of examples of small, medium and high power. A table for each category with perhaps 20-30 examples would be a great cross reference and information resource. It doesn't seem to make sense to spread it over a large number of pages as the same information will tend to be repeated time and again. Nick Hill ( talk) 19:01, 26 July 2015 (UTC)
Typical values. Refer to specific manufacturer's data sheets. Case numbering looking from below. TO18 pin 1 next to tab, counting clockwise. TO92 flat facing up, 1 to the left.
Part Number |
Type | Ic (ma) | Vcb | Vce | Hfe | Ft | Ptot (Mw) | Pin Layout 1 2 3 |
Case | Notes |
---|---|---|---|---|---|---|---|---|---|---|
BC546 | NPN | 100 | 80 | 65 | 100-800 | 300 | 500 | C B E | TO92 | Linear gain [1] |
BC556 | PNP | 100 | 80 | 65 | 100-800 | 150 | 500 | C B E | TO92 | Linear gain [2] |
BC107 | NPN | 100 | 50 | 45 | 100-800 | 150 | 600 | E B C | TO18 | Replaced with BC547 [3] |
BC547 | NPN | 100 | 50 | 45 | 100-800 | 300 | 500 | C B E | TO92 | Linear gain [1] |
BC557 | PNP | 100 | 50 | 45 | 100-800 | 150 | 500 | C B E | TO92 | Linear gain [2] |
BC108 | NPN | 100 | 30 | 25 | 100-800 | 150 | 600 | E B C | TO18 | Replaced with BC548 [3] |
BC548 | NPN | 100 | 30 | 30 | 100-800 | 300 | 500 | C B E | TO92 | Linear gain, Low noise [1] |
BC558 | PNP | 100 | 30 | 30 | 100-800 | 150 | 500 | C B E | TO92 | Linear gain, Low noise [2] |
BC109 | NPN | 100 | 30 | 25 | 100-800 | 150 | 600 | E B C | TO18 | Lower noise version of BC108 Replaced with BC549 [3] |
BC549 | NPN | 100 | 30 | 30 | 100-800 | 300 | 500 | C B E | TO92 | Linear gain, Low noise [1] |
BC559 | PNP | 100 | 30 | 30 | 100-800 | 150 | 500 | C B E | TO92 | Linear gain, Low noise [2] |
BC550 | NPN | 100 | 50 | 45 | 100-800 | 300 | 500 | C B E | TO92 | Linear gain, Low noise [1] |
BC560 | PNP | 100 | 50 | 45 | 100-800 | 150 | 500 | C B E | TO92 | Linear gain, Low noise [2] |
2N3904 | NPN | 200 | 60 | 40 | 30-300 | 270 | 625 | E B C | TO92 | Non-linear gain [4] |
2N3906 | PNP | 200 | 60 | 40 | 30-300 | 250 | 625 | E B C | TO92 | Non-linear gain [5] |
2N2222A P2N2222A |
NPN | 600 | 75 | 40 | 35-300 | 250 | 500 | E B C C B E |
TO18 TO92 |
Non-linear gain [6] |
Nick Hill ( talk) 19:47, 26 July 2015 (UTC)
References
Why do Pro Electron devices come in JEDEC packages? Surely they would at least have come up with their own metric packages. -- Wtshymanski ( talk) 03:27, 4 April 2011 (UTC)
This part number is not notable and is not a suitable topic for an encyclopedia article. Even history books about the semiconductor business don't spend any time on individual part numbers, because they aren't important to understanding semiconductors and thier roles. -- Wtshymanski ( talk) 13:38, 5 April 2011 (UTC)
The BC548, and the family it belongs to, are VERY notable in Europe and places like Australia/New Zealand, but some of the comments on this page are understandable given the way that some types were famous in half of the world but hardly known in the other half. There are many references that could (and should) be brought in to show the significance of the family that can be described by the neat table:
Case | Polarity | 80Vcbo | 50Vcbo | 30Vcbo | Low-Noise 30V | Low-Noise 50V |
---|---|---|---|---|---|---|
TO-18 | NPN | BC107 | BC108 | BC109 | ||
PNP | BC177 | BC178 | BC179 | |||
Lockfit | NPN | BC147 | BC148 | BC149 | ||
PNP | BC157 | BC158 | BC159 | |||
TO92B (e-c-b) |
NPN | BC167 | BC168 | BC169 | ||
PNP | BC257 | BC258 | BC259 | |||
TO92F (c-b-e) 350mW |
NPN | BC237 | BC238 | BC239 | ||
PNP | BC307 | BC308 | BC309 | |||
TO92A (e-b-c) |
NPN | BC317 | BC318 | BC319 | ||
PNP | BC320 | BC321 | BC322 | |||
TO92F (c-b-e) 625mW |
NPN | BC546 | BC547 | BC548 | BC549 | BC550 |
PNP | BC556 | BC557 | BC558 | BC559 | BC560 | |
SMD | NPN | BC846 | BC847 | BC848 | BC849 | BC850 |
PNP | BC856 | BC857 | BC858 | BC859 | BC860 |
(see also:
[1] for a neat summary of some of the family).
One typical reference is: [2], another is a news item in Practical Wireless (I think it was) when the grandparents of the family were introduced around 1966 (I don't have that reference to hand, but could find it). The fact is that the BC107/8/9 family became the most common types to be specified in magazine articles and so on for many years after the days of the OC71 and before the plastic versions BC547/8/9 took over. The Australian Philips "MiniWatt" article I just mentioned begins with a statement saying how important the BC107/8/9 transistors were.
Where the criticisms on this page have something worth noting is that there is a lack of encyclopedic information, and this could and should be expanded. The article should show:
I certainly think the BC548-family article is needed, and trying to cover this only in something spanning all BCxxx types would be a mistake - it is too notable a group of transistors. Maitchy ( talk) 00:17, 17 March 2014 (UTC)
Most of this article isn't about its putative subject. Aside from the parts list data sheet numbers, we still haven't been told anything about *this* transistor type. What company first registered it, and when? Is it still made? Are as many being made now as in, oh, say, 1978? Do we know anything notable about this transistor at all? -- Wtshymanski ( talk) 18:48, 17 April 2011 (UTC)
What is the purpose of this page? So far I see
If people want datasheet type content, there's a vast amount of it available, and someone could write thousands of new pages. 82.31.207.100 ( talk) 14:48, 24 July 2011 (UTC)
I came to this article because I am doing up a circuit that uses the BC548, and it isn't as common in North America as it is in Europe and the UK. So I thought: I'll read up!
The article, before I went to work on it with a few dozen or more edits, was tagged as Refimprove and "incomprehensible", or "too technical". I have to agree. It was a fairly large assortment of very technical info. I made quite a large number of edits based on the following:
In any case, I think it now reads well. It brings out the main points:
For more info, see datasheet! HappyValleyEditor ( talk) 02:36, 8 March 2016 (UTC)