EEVblog 1599 - TOP 5 Jellybean Bipolar Transistors - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: February 18, 2024, 09:32:27 pm
content: The TOP 5 Jellybean Bipolar Junction Transistors (BJT)00:00 - What is a Jellybean Component?01:30 - Low Power BJT: 2N3904 / 3906, SMD Marking 1A06:49 - 2N222208:52 - BC547 fanboys09:28 - Medium Power BJT: FMMT617-619 / 717-71912:27 - SS8050 / 855015:08 - High Power BJT: 2N3055 / 295517:09 - Sneaky MOSFET, and the differences from BJT's19:30 - High Voltage BJT: FZT458 / 558, FMMT458/558Jellybean Series Playlist:https://www.youtube.com/playlist?list=PLvOlSehNtuHv268f0mW5m1t_hq_RVGRSA

author: tocsa120ls
author_rank: Regular Contributor
timestamp: February 19, 2024, 05:37:34 pm
content: I respect the elders; I do have some 2N3055 and BC182s laying around!

author: nctnico
author_rank: Super Contributor
timestamp: February 19, 2024, 08:49:23 pm
content: Next up: Jellybean mosfets. At least these don't need Lithium to stay sane...

author: SeanB
author_rank: Super Contributor
timestamp: February 19, 2024, 09:04:31 pm
content: There are not many jellybean SCR's and TRIAC's, other than the C106x, and the BT132, which are generally the most common ones you get. There are no jellybean UJT's though, and same for the more esoteric highly doped devices that used to be common in use.

author: squadchannel
author_rank: Frequent Contributor
timestamp: February 20, 2024, 10:23:58 am
content: 2SC1815/2SA1015 most popular bjts in japan

author: Kleinstein
author_rank: Super Contributor
timestamp: February 20, 2024, 10:39:27 am
content: The European naming scheme includes the case. The BC547 as SMD (sot 23) is a BC847. The same silicon as the BD135 is available different cases, e.g. as BC635, BCP54,BCX54. The american style naming with different letter in front makes it a bit easier to find the similar versions.In the strict sense the 2N2222 is only the TO18 metal case version and this is not longer that common any more. It's still the most common transistor in the TO18 case though.

author: Steffen
author_rank: Regular Contributor
timestamp: February 20, 2024, 04:29:57 pm
content: I usually also keep BC548/BC558 and 2N4401 on hands. BD139 can also work well as base driver for 2N3055 in linear regulated power supplies. I missed the 2N2219 in the video.

author: Ranayna
author_rank: Super Contributor
timestamp: February 22, 2024, 07:48:25 am
content: The BC548 will always have a place in my heart as the very first transistor i ever used. It was included in my Kosmos X1000 kit.From what i know, the BC and BD Series were more an european thing, while the 2N series was an american thing.

author: coppercone2
author_rank: Super Contributor
timestamp: February 22, 2024, 07:53:05 am
content: the 3055 is my favorite

author: SiliconWizard
author_rank: Super Contributor
timestamp: February 22, 2024, 08:07:53 am
content: Quote from: squadchannel on February 20, 2024, 10:23:58 amI remember all these 2SC BJTs in audio amps, they were pretty well regarded, not sure the reputation was justified in hindsight, but these were fun days.

author: David Hess
author_rank: Super Contributor
timestamp: February 24, 2024, 06:21:26 pm
content: For me the 2N4401/2N4403 replaced the 2N2222/2N2907 long ago, and I have yet to find an application where they cannot replace the 2N3904/2N3906 as well.My jellybean transistor list would also include a fast low capacitance pair like the KSA1381/KSC3503 or KSA1142/KSC2682. When needed they really have no alternative.My jellybean high power pair has become the D44VH10/D45VH10 which are ring emitter transistors suitable for fast regulators, audio amplifiers, and such in place of the 2N3055/2N2955.That leaves an RF pair, a fast saturated switch pair, and a low current pair, but so many parts have been discontinued that they are difficult to select now.

author: djsb
author_rank: Super Contributor
timestamp: February 24, 2024, 06:53:29 pm
content: The first transistors I ever used were BC107,BC108 and BC109. Still use them now where I work. I may even have used an OC71 Germanium at one point when I tried making the radio from this book when a young lad.https://www.worldradiohistory.com/BOOKSHELF-ARH/Technology/Making-a-Transistor-Radio-Ladybird%20Books-1972.pdf

author: Excavatoree
author_rank: Frequent Contributor
timestamp: February 24, 2024, 07:01:52 pm
content: Quote from: squadchannel on February 20, 2024, 10:23:58 amI changed a lot of 2SA, 2SC, and even 2SD transistors when I worked at the electronic repair shop, many years ago. (mostly in FTR packages, which I don't see anymore) Back before the internet was what it is today, I bought a Japanese transistor manual because I'd strip the abandoned units for parts. I still have those transistors.

author: G0HZU
author_rank: Super Contributor
timestamp: February 24, 2024, 09:52:55 pm
content: For small signal stuff, the 2N3904 is a fairly decent RF transistor. It's generally better than the other jellybean types in this respect. This assumes it is a genuine 2N3904 made with process 23.This isn't always a good thing, as the 2N3904 is going to be able to go unstable at higher frequencies than other jellybean parts like the BC547B or 2N2222A. The 2N3904 can easily go unstable up at 800-900MHz and should be able to oscillate above 1GHz. This sets it apart from the others. Some extra care is therefore needed with the PCB layout for some RF amplifier circuits.

author: magic
author_rank: Super Contributor
timestamp: February 24, 2024, 10:25:08 pm
content: Quote from: SiliconWizard on February 22, 2024, 08:07:53 amThese transistors have good "beta linearity", i.e. it doesn't vary with collector current much, and this was clearly spelled out in the datasheets.In audio, it removes one source of distortion, particularly in class A stages where pair matching is not an issue and particularly in amplifiers with barely enough current gain to function.

author: David Hess
author_rank: Super Contributor
timestamp: February 25, 2024, 01:14:50 am
content: Quote from: magic on February 24, 2024, 10:25:08 pmThat usually means that they were built using a ring or perforated emitter structure, like the D44VH10/D45VH10 which I mentioned. This structure produces less beta droop and Ft droop at high currents. They are also suppose to have a better safe operating area, but they seem about the same to me. Their only disadvantage may be that their higher Ft means that they are more prone to parasitic oscillation, but so are MOSFETs.

author: David Hess
author_rank: Super Contributor
timestamp: February 25, 2024, 01:20:16 am
content: Quote from: G0HZU on February 24, 2024, 09:52:55 pmThe jellybean RF transistor that I used to rely on is the MPSH10/MPSH81, but they are discontinued at this point. For higher frequency baseband stuff, I wanted to standardize on the PNP/NPN RF pairs from NXP, but they are also discontinued.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 25, 2024, 03:21:50 am
content: Quote from: David Hess on February 24, 2024, 06:21:26 pmWell, I've made plenty, but in the context of jellybeans, that'll be mostly true. (Though it's not clear how "jelly" you mean your "beans" to be, here.) 4401/3 are, or at least can be, quite low leakage, and good hFE even at low currents, so you aren't gaining much from the small junction of a 3904 -- just the capacitance, where speed matters.2N4401/3 themselves go quite fast, I've had sub-20ns edges out of them before, but you have to cook quite hot to get there, 20mA say. 3904 do the same at lower current, of course, and MPSH/MMBTH10/81 even moreso.QuoteI would definitely not put CRT drivers in a jellybean category; but if so, then the 3904/4401 difference above is definitely relevant. But in any case, their "beaniness" is just a matter of classification.Having small-junction drivers for high-performance audio amps, and the occasional special-purpose driver (Idunno, piezo? legacy/vintage projects like CRTs?), is definitely nice, and that's one of the best types.D44xxx are, surprisingly -- shockingly even? -- old designs, but pretty much as good as any modern Sanken, onsemi, etc. device today. They date to what, the 70s or so? Very underrated parts, it seems like.Hmm, not sure how general that perception is; the naming scheme I think is from GE? So that dates it pretty far back at least. It may be just that, a naming scheme, with all matter of types there, and only the D44VH10, and close relatives, survived the test of time. *shrug*As with 2N2222, my gripe with 2N3055 is the trash spec; you don't know what you're going to get. Most parts today will be high performance epitaxials, comparable to MJ15020-something or other for example, but almost anything can fit the spec so you don't really know for sure. You can at least rest somewhat soundly knowing that nobody's making those trash (relatively speaking) homotaxials anymore... but you also have no guarantee you won't be shipped vintage parts perfectly in spec. Safer to just buy the thing you want in the first place.If it's not an outright counterfeit, of course. People have seen 2N3904-size dies inside the poor things before... But, that's more of a supply chain issue, than a matter of specs.QuoteBFT/BFR92 used to be an amazing pair, but the PNP's now long gone (probably still good stocks of it to be found, if you really need to?), and variants of the NPN even I think are obsolete or soon to be. Even MMBTH10 is on the chopping block...Quote from: G0HZU on February 24, 2024, 09:52:55 pmSpeaking of, did you realize -- actually, you probably do since mentioning it by name, but I don't recall seeing this until relatively recently when I was flipping through databooks. Anyway, 2N3904 is (or, was) gold doped!http://www.bitsavers.org/components/national/_dataBooks/1971_National_Transistors.pdfWhich should indeed run pretty fast, but should also have poorer hFE at low Ic due to stronger recombination, and I think most modern parts don't do that so much. I wonder if they indeed use gold doping still, or skip it entirely. Or perhaps the dosage is different.That would explain an observation I saw recentlyish -- not so recently I have the link handy unfortunately, or recall precisely what was in question, but it was something like comparing the storage time of various components, and I was shocked that someone mentioned BC847 has quite long storage; or maybe it was (E-B or C-B) recovery. My measurements of 2N3904 disagreed, but if others are not gold-doped where 3904 is , that might explain that in part.As for RF stuff, much like MOSFETs, there's no jellybean as such -- the market is constantly changing, and no part remains relevant for very long.There's still the most prominent of HEXFETs, IRF540s and such, IRFPs for higher power, stuff like that. Performance stinks, but not enough to matter -- in relative terms, it's bad, it's about 5x worse than modern equivalents, but in absolute terms, you just want to switch a solenoid or something, hell yeah, it works just fine.The same technology (HEXFETs, or more generally anything planar, non-trench, non-superjunction) lives on, reborn in boutique form, as "linear" MOSFETs -- at least, as far as I know, this is what Littelfuse (nee IXYS) is doing with such product lines, and, I don't think anyone else is offering "linear" parts as such so it's pretty much their little corner.Shockingly, a lot of SJ parts boast full SOAs, despite the power density being higher than ever. Not sure how or why, but, hey, I'm not complaining. You might (rightfully) wish to spot-test parts and make sure the SOA isn't lying to you, but the checks I've done, have been promising.Have even seen some IGBTs with DC SOAs, which... okay, I guess!?Reallycurious how they pull that off, or, why?, but, there it is.But yeah MOSFETs, shop for the Vmax, Rds(on) and Qg you need, and that's about it. See what Pd is available, packaging, go back and forth with a few design iterations, and settle on a combination that works.Honorable mention for product families, if not parts specifically, or manufacturers: (They all make these types, so take your pick.)1. At low voltages, pretty much everything is trench something or other.1a. TI's NexFET, being the most exceptional; they, uh I guess still use a trenching process but not in the active region..! They use a sort of wrap-around structure that acts like a single-piece SJ structure, as well as a cascode. The Crss is *extremely* low, to the point the Miller step is barely perceptible.2. At high voltages, pretty much everything is SuperJunction, with the "tell" that the Coss(Vds) curve drops precipitously at ~20V. (It's not a planar junction at all, C(V) is allowed to drop much much much faster than (1 - V/VJ)^-m, and indeed can take absurd values like infinite or negative incremental capacitance because of how it's shaped.) This is true even for cheap Taiwanese and Chinese parts, which are offering very good specs these days.2a. These are available in "fast" and "slow" grades, as far as body diode recovery. Most things, it doesn't matter, but for resonant converters, you might prefer fast recovery. The avalanche rating may vary between these types as well. Compare Vishay E vs. EF series for example.3. Mainly when you need the speed, but also for efficiency, and higher voltages or more compact designs: consider wide bandgap types. SiC have very attractive ratings, improved speed, and only modestly increased drive voltage requirements; voltage ratings go to 1700V or more (apparently there are 10kV parts, both MOS and IGBT, but you probably have to sign over all sorts of special information to even peek at datasheets, let alone real parts?). GaN are mostly low voltage, with newer families pushing over 600V now; they'rescaryfast, so must be used carefully. GaN have no avalanche capability by the way (or, I've yet to see one so rated), so I mean that doubly so.SJ bears the distinction of having, effectively, dielectric losses; basically as the pillars deplete, they get cut off (they act as opposing JFETs pinching each other off), and charge has to flow through their lengthwise resistance to escape. This is avoidable with very slow edge rates (>100s ns?), but most of the time you just have to accept it. This limits the efficiency of resonant converters (a bigger device has lower conduction losses but proportionally more dielectric losses), so choose different technology if absolute maximum efficiency is required. (As I understand it, SiC are basically ye olde ~200V Si MOSFET designs, ported to a new material; and I mean that literally in terms of feature size and stackup, if obviously not in terms of doping and whatever. So, they aren't SJ, and don't suffer from its loss mechanism. The higher voltage types might.)Don't be afraid to use SMTs, either; DFN packages have extremely low inductance, and can be heatsunk quite effectively, in combination with wide pours, thermal vias and inner planes. You shouldn't be dissipating much power, anyway; use switching to your advantage, and optimize Rds(on) vs. Coss to suit the application. (Lowest possible Rds(on) is rarely the way to go! That said, as figure-of-merit keeps improving, you can pick quite low-resistance types these days, and still reap improvements.)Basically, buy some types as needed, and say in a production context, write up some detailed selection rules for how to choose substitutes. Expect EMI changes if Qg, FoM, etc. differs notably, and watch for avalanche, dV/dt etc. where ruggedness matters (not that anyone offers repetitive avalanche ratings anymore, and you shouldn't be making use of it in a real application anyway; get a TVS in there if you must!).Tim

author: David Hess
author_rank: Super Contributor
timestamp: February 25, 2024, 12:11:48 pm
content: Quote from: T3sl4co1l on February 25, 2024, 03:21:50 amThe higher current capability of the 2N4401/2N4403 also results in better hfe at what would be high currents for the 2N3904/2N3906.I might replace them with one of the modern low Vsat parts which support amps, which Dave mentioned, however the modern low Vsat parts are so much more expensive and no jellybean type of part has come out of them, at least that I know of.QuoteThey are commonly used for voltage amplification stages where linearity matters, but their low capacitance also makes them useful for fast switching and level shifting where other parts cannot compete. I never appreciated how useful these types of transistors are until I investigated one of the level shifting stages in my Tektronix 547 and discovered that Ic/Co can be a figure of merit.I also use them as medium power drivers rather than having a separate part for this, although Dave mentioned the BD139. If I did pick a medium power driver, then it would be a ring emitter part like the MJE182/MJE172 or MJE243/MJE253, or perhapse the BD139/BD140 or KSA1220A/KSC2690 although I am not sure how the later are constructed as they seem to be a different class of transistor.QuoteOn Semiconductor and some others make these types for audio, and some big ones, but the D44VH10/D45VH10 are the surviving jellybeans of the type and there is a whole series with that naming scheme. Tektronix used them as replacements for 2N3055 types in their last oscilloscopes for the high voltage inverter, and they also made a reappearance in fast response linear regulators for CPUs.If there were other types of parts in that series, I do not know of them although I have databooks going back that far so I could check. The MJE182/MJE172, which I mentioned above, work well as drivers for them and are useful on their own where lower power is acceptable. Originally I suspect lessor versions of the D44VH10/D45VH10 were used as drivers, and still could be where available.QuoteFor a while the Japanese were making complementary linear IGBT pairs for audio, but ultimately they did not catch on. I suspect availability was restricted to maintain a competitive advantage, but that this also made them uneconomical.

author: jonpaul
author_rank: Super Contributor
timestamp: February 25, 2024, 12:55:14 pm
content: 2N36422N3638Fairchild core mem drivers, have used 1960sj

author: G0HZU
author_rank: Super Contributor
timestamp: February 27, 2024, 06:37:11 pm
content: QuoteHi, yes I have a similar Nat Semi databook here. Mine is the 1978 version and it lists lots of process types and shows the die for each. The shape of the die for process 23 gives a clue that the 2N3904 is quite different from (say) the BC107 (process 04).I think the MPSH10 and MMBTH10 are process 42. I've got quite a few of these BJTs here and they definitely need to be used with care. Especially when used as a common base RF amplifier. They can easily go unstable up at around 2GHz and can probably oscillate up as high as about 2.4GHz.

author: David Hess
author_rank: Super Contributor
timestamp: February 28, 2024, 03:43:05 am
content: Quote from: jonpaul on February 25, 2024, 12:55:14 pmI always wondered what distinguished core memory drivers from other medium current/power transistors.Quote from: G0HZU on February 27, 2024, 06:37:11 pmI was always puzzled by that. The National Semiconductor discrete databook says that the 2N3904 is fabricated on their gold doped process, and Bob Pease warned that 2N3904s from some manufacturers cannot be relied on for low leakage because they are gold doped, but I never found a National Semiconductor 2N3904 with the high leakage or low hfe or high speed that would be associated with gold doping, so I always wondered if their databook was wrong.Quote from: G0HZU on February 27, 2024, 06:37:11 pmTektronix liked using them, and their PNP complement, for 100 MHz discrete oscilloscope circuits. The 2N3904/2N3906 are not quite fast enough.I tested them and concluded that RF transistors, whether gold doped or not, are not replacements for fast saturated switching transistors, which unfortunately are now few and far between.

author: Kleinstein
author_rank: Super Contributor
timestamp: February 28, 2024, 08:50:40 am
content: The gold doping should mainly effects the storage time, not so much the ft part of the speed. So the gold doping would help with switching, not so much with linear amplification.The gold doping can also be at a moderate level. There is not just the question doped or not. Similar to the fast diodes: there are the really fast ones with a trr of some 4 ns and the moderately faster ons with some 100 ns with a lower level of gold (or other dopant to add recombination centers).For really fast saturated switching there is the classic 2n2369, that is also available as SMD version MMBT2369 (and similar). For this application (though already a bit special) one can consider it a yellybean type. Here the high speed comes with a rather high leakage. So this transistor is quite a bit different from the normal small signal types.

author: RoGeorge
author_rank: Super Contributor
timestamp: February 28, 2024, 02:47:22 pm
content: Hmm, SMD jellybeans?! I always thought of jelly beans components as through whole, and pictured them like in the typical advertising from the 70's...90's electronic magazines: in a big bowl, or a huge glass, filled with a bulk of all kind of components.

author: Muxr
author_rank: Super Contributor
timestamp: February 28, 2024, 02:56:08 pm
content: Quote from: RoGeorge on February 28, 2024, 02:47:22 pm"italsocomes in SMD".That I think is an important feature of every jelly been part. You may want the through hole for prototyping and messing about, but having an option to get them in SMD for use in SMD designs is also quite important. For folks who may want to produce more than a few boards using those parts.Also since they are jelly bean parts, it's handy to have some in SMD form factor because you may need them for repairs.

author: G0HZU
author_rank: Super Contributor
timestamp: February 28, 2024, 11:18:30 pm
content: Quote from: Kleinstein on February 28, 2024, 08:50:40 amYes, the 2N2369A is a classic high speed switching device (process 21). Many years ago I used the 2N2369A quite a lot as the active device in classic Colpitts crystal oscillator circuits. It performs well in this application.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 29, 2024, 12:12:41 am
content: I have a number of them (Philips TO-92 PH2369A) removed from CRTs, back in the day, along with some BFQ221/225/241. Together, they were the bottom/input (2369), top/cascode (BFQ225), and complementary emitter follower (221/241), in the cathode video driver circuit. Probably was from around the time when ASICs were just taking over; late 90s/early 2000s? -- the N3 chassis Trinitron I was using for a long time, dated from 2001 I think and used such a chip.Not exactly pushing bandwidth boundaries for ~100MHz video, but shows their use in a linear/amp circuit anyway.Also have some... I'd have to go look up the part, but they're something like 20V 1A 1.something GHz transistors, in a... wide thick plastic package somewhat like a TO-202 without any tab at all, which were the bottom cascode in some other monitors I took apart way back when. Interesting devices to be sure.Tim

author: David Hess
author_rank: Super Contributor
timestamp: February 29, 2024, 01:27:45 pm
content: On a different subject, I went hunting for current jellybean TO-92 parts:BC546C/BC556C 65V 100mA High hfe Amplifier2N3904/2N3906 40V 200mA Amplifier/Switch2N4401/2N4403 40V 600mA Amplifier/Switch2N2222A/2N2907A 40V/60V 600mA Amplifier/SwitchBC337-40/BC327-40 50V 800mA Amplifier/SwitchThe KSA1381/KSC3503 is now the only more powerful extra linear part that is still available, albeit at 10 times their original cost. The TTC015B/TTA008B and MJE340/MJE350 might be possibilities, but would need to be tested because their datasheets are incomplete. The figure of merit here is something like Ic/Cre. I did not check for surface mount alternatives.Quote from: Kleinstein on February 28, 2024, 08:50:40 amPlenty of RF transistors are gold doped. I tested a bunch of old and new small signal RF transistors and none were suitable replacements for fast saturated switches even when Ft was much higher. I concluded that there is some basic difference in construction besides gold doping.Baker clamping of an RF transistor reduces storage time, but increases saturation voltage.QuoteWhere they are still available, the remaining ones are difficult to find. One thing to look for is low Vceo of 12 volt for NPNs and 15 volt for PNPs.My most recent survey from a couple years ago for SOT-23 parts includes:NPN:MMBT3646BSV52MMBT2369AMMBT2369PNP:MMBT5771MMBT3640I also have the list of saturated switches that Tektronix used:NPN, in order of Ft:2N2501 350 MHz2N5769 400 to 500 MHz2N2369 500 to 650 MHzPNP, in order of Ft:MPS3640 500 MHzPN4258 700 to 900 MHz