[Robert Latest]

Do IC fabs often use gold doping?

I've never heard of that. I think gold and other alchemy is what keeps
discretes fabs alive and kicking in ol' US and Europe.

(Yes, I know a
designer can use circuit schemes instead to reduce
storage time.) Are there other gold-doped discrete
transistors we should know about?

I need to look, but I think NXP's 3904 and 3906 (complementary) are gold
doped. The 3904 uses the same process as the BSR13, and I know that
BSR13 has a gold doping step.

robert

 

[Robert Latest]

Here's a couple of On Semi's low Vce sat bjt's.They are a little
pricey but still cheaper then diodes comparable FMMT series.

Good call! NXP also have a similar line (called BISS), I don't know how
they compare to ON's stuff.

robert

 

[Joerg]

John Larkin wrote...

I'd also throw the BSS84 for P-channel into the hat. It's my jelly-bean
part.

Hah!


Yep, very small die.


What, no PNP equivalent?

I've got BFT92 and BFT93 in the table.
How does the BFT25 compare to the BFT92?

The BFT25 is NPN. Phil Hobbs should be able to give a good account on
that one.

While we're at it, what other categories do you need hints for? For
example, for drivers con mucho gusto the MIC4421/22 series is great but
hardly any young engineer knows about stuff like that.

Oh, and tell readers not to blindly trust POR/BOR circuitry inside a uC ;-)

Can't hurt to mention some of the budget rockets, like the BFP620, but
with the usual caution notes (like that it might be oscillating without
even noticing it, until a government van shows up ...):

http://www.infineon.com/dgdl/bfp620...205c5&fileId=db3a30431400ef680114274deb27072a

 

[Joerg]

Eww-w-w-w-w! At least MJ15001/2. MJ15031/2 are even better. Actually, if
you must have TO-3, anything MJ150xx is good. Almost anything good comes in
TO-247's these days, TO-3 really is ancient now.

Speaking of power transistors: high voltage switches - MJE13003 (~1.5A, used
in CFLs), MJE18009 and such (450V, >5A), and usually available in fullpak
too (MJFx), plus a whole slough of Japanese equivalents (off the top of my
head, 2SC2625, 3306, 4020, etc.). Fairchild and a bunch of others have
their lines of second sources and similar parts. Maybe not as useful for
textbook examples (where you'd rather show a stately MOSFETs handling an
SMPS, not those fifty cent whore BJTs! ).

Other power transistors include TIP29-32, obviously, plus the old
TIP112/120/etc. darlingtons, good for linear apps and slow switching.

2SD1273 is a superbeta power transistor, 2A 30V full pack. Really odd find,
and not all that useful, but it does make an excellent replacement for a
darlington when you need low Vce(sat)!

For general high beta, 2N5088 is jellybean. Not really superbeta, but up
there. I think one of those BC's Win started off with, BC547C, comes in
obscenely high beta as well (the C grade).

I recently looked up some highish frequency jellybean sorts of transistors,
but now I can't find where I put the list...

Might also want to sprinkle in some jelly-bean power FETs like the
IRF640. They are used everywhere.

 

[Hammy]

Good call! NXP also have a similar line (called BISS), I don't know how
they compare to ON's stuff.

robert

I think they all have low Vce sat BJT's now. For example Fairchild's
got these;

FSB560 NPN - 2A; 60V; SOT-23

http://www.fairchildsemi.com/ds/FS/FSB560A.pdf

FSB660A PNP - 2A; 60V; SOT-23

http://www.fairchildsemi.com/ds/FS/FSB660A.pdf

I've never used those two but they are cheap a dime for the NPN at
Newark; the PNP isn't stocked.

A quick search of Fairchild shows at least 6 low sat bjt's ranging
from 1 amp to 3amps.

Another decent one from Onsemi I have used and have is the

MBT35200MT1 PNP - 2A; 35V; TSOP-6

http://www.onsemi.com/pub/Collateral/MBT35200MT1-D.PDF

I do prefer On semis datasheets to Zetex/Diodes, and stateing the
equivalent Rdson is a good idea for quick comparisons.

 

[Okkim Atnarivik]

Cool.

Fig 4 is impressive, but "base grounded" implies that it will be
useful only for very low source impedances. Transformers get

Current noise is in the ballpark of 4.5 pA/rtHz, which makes it
approximately to noise-match with a 50ohm source at an order-of 40K
noise temperature. The frequency range extends at least up to
100 MHz but probably still much higher, even with the tranquilizers
present.

I have had difficulties to wind really wideband transformers on
low-loss cores in the past. The sporadic commercial transformers
I've tried tended to have to high-enough losses to eat the noise temp.

interesting in such situations, or *lots* of opamps or jfets in
parallel, which will be better at low frequencies.

True, done that in the past, with BF862's for instance. It just
gets complicated, and in wideband designs you may create curious
oscillation modes. In the sub-10kHz you can indeed do better with
some other amps.

Regards,
Mikko

 

[Joerg]

Okkim Atnarivik wrote:

[...]

True, done that in the past, with BF862's for instance. ...

^^^^^

Hey, Winfield, Mikko just brought another excellent one for the
jelly-bean list. This one has got to be in there, very low pinch-off
JFET, steep enough to start an oscillator from less voltage than a fuel
cell provides. Very useful.

How could I have forgotten, oh, this will haunt me, the wrath of the old
Philips engineers will come upon me ...

 

[Okkim Atnarivik]

Hey, Winfield, Mikko just brought another excellent one for the
jelly-bean list. This one has got to be in there, very low pinch-off
JFET, steep enough to start an oscillator from less voltage than a fuel

Yes, but he asked for BJTs...

 

[Joerg]

Yes, but he asked for BJTs...

Ok, then just make it a "bonus delivery" of ideas

Oh, Winfield: Please mention in your book the fact that there are
newsgroups such as this one if people get stuck, need circuit ideas or
want to help youngsters. Most people who buy the book nowadays don't
have the foggiest what Usenet is. When I bought my AoE way back when I
did not know sci.electronics.design either.

 

[Joerg]

I've been around here so long I started out reading and posting using
TIN ;-)

I did let off a few posts back in the early 80's using a service called
"Datex" but I have no idea whether that forum was related to Usenet. You
had to go into the basement of a university building. Then you had to
find someone with a key to the computation machine room who was able to
fire up the machine with all them blinkenlights. There were also a few
Juki card punching machines.

 

[Okkim Atnarivik]

: I've been around here so long I started out reading and posting using
: TIN ;-)

Amusing, I'm posting this from TIN right now. I thought it is a pretty
modern newsreader, at least the university used to provide some other
programs in the past years.

Regards,
Mikko

 

[Paul E. Schoen]

I'd also throw the BSS84 for P-channel into the hat. It's my jelly-bean
part.

I still like the 2N3819 N-channel JFET. I used it in an audio preamp I
built as a hobby project around 1970, and I used it in an analog
programmable-gain amplifier I designed around 1985. It's still available
from Mouser for 10 cents each, and is still made by Fairchild.
www.fairchildsemi.com/ds/2N%2F2N3819.pdf

Also, it's first on the list of devices in LTSpice!

Paul

 

[Tim Williams]

As far as I can tell, TIN is still maintained, and quite up-to-date.

I used it on dial-up, (IIRC) early '80's.

Big deal, I was just browsing this newsgroup from a TCP/IP terminal.

Tim

 

[krw]

I've been around here so long I started out reading and posting using
TIN ;-)

You've been around so long that you witnessed the invention of tin.
;-)

 

[Fred Bartoli]

Jan Panteltje a écrit :

I have a lot of BF245, only about 6.5 mS, but very nice to have around.
If I was to stock up on MOSFETS I would get more IRLZ34N, low voltage on,
high current, avalanche protected.

On a desert island that would be a nice feature to protect you against
tsunamis.

 

[Tim Williams]

On a desert island that would be a nice feature to protect you against
tsunamis.

You're right, better throw in some IGBTs for the tidal generators!

TIm

 

[krw]

Not quite. Wikipedia says tin plating has been done for "hundreds of
years".

Tell me, how did they first make bronze? ;-)

I'm still young (at least of mind):

I turn the big 7-0 at the end of this month (actually 17.5 birthdays
;-)

I believe that would be the fist of next month (isn't that the
*official* birthday?).

The end of March, "N" and I will celebrate the big 5-0 anniversary!

Long time. June will be 39 for us.

 

[JosephKK]

Not quite. Wikipedia says tin plating has been done for "hundreds of
years".

I'm still young (at least of mind):

I turn the big 7-0 at the end of this month (actually 17.5 birthdays
;-)

The end of March, "N" and I will celebrate the big 5-0 anniversary!

...Jim Thompson

Family time, then "N" and you time. Have a lot of fun.

 

[Ban]

If you were stuck on a desert island and could only have one jfet, it
would have to be the BF862. Gm is 45 mS and noise is 0.8 nv/rthz.
There's nothing else like it.

I would prefer a cute girl rather than a FET on that Island what's the FET
without soldering iron and for the girl you don't need a soldering iron
don't u?

 

[Ecnerwal]

ftp://jjlarkin.lmi.net/Bent_Icycles.jpg

Yeah, it does that. I get confused about where you are at - Mostly (&
company) seems to be SF, where I somehow doubt this picture is taken,
but you mentioned Charlemont once when burning brush while using wi-fi.
That seems more likely for this picture. Just over the mountain with the
hole through it from me if you are there.