2SK127 -- what to use them for?

[Wavebourn]

I once bought couple of plastic bags of some transistors. The seller said they were in-house marked 3904 and 3906. Yesterday needing some cheap PNP switches I opened the bag and found that no way they are BJTs, they behaved like N-type JFETS.
They marked like:

$127
5126
O

where $ I used instead of National sign.
I've searched the web and found that indeed there were such 2SK127 N-type JFETs, but still can't find any details.

The question is, what they are best for?

NPN transistors are marked as:

4500l
3500
EBCi

They are not Darlingtons, and Beta is around 150.

[lineup]

2SK127. They are LF FET transistors (not low-noise) but Cis, Crb is low.
Takes 50 Volt! The gm is Minimum 4mS
Here are some data:
http://www.minor-audio.com/data/2SK/2SK0101-0200.htm


=============================================

At the same website this guy has lots of stuff/schematics
dealing with NO-NFB amplfiers
http://www.minor-audio.com/bibou/bibou.html

For example this:
NO-NFB MOS-FET 15W パワーアンプの製作


The 15 Watt Amplifier


+-35 Discrete Regulator for the MOS-FET 15 W

Webpage: http://www.minor-audio.com/bibou/NO-...NFB_main2.html

[lineup]

Toshiba 2SK330 is one equivalent to 2SK127
http://www.datasheetcatalog.org/data...shiba/1033.pdf

A look shows most of the data is very much comparable

[Wavebourn]

Thanks Lineup!
I have more than couple of thousand of good P - type jfets instead of small PNP transistors...

[Wavebourn]

Hmmm.... It's strange, but I've found another info, quite contradictory (mine are P-jfets according to brief measurements, like on your link):

Specsheet from Matsushita Electric Works, Ltd.
2SK127
N-Channel JFET

V(BR)GSS (V)=80
I(D) Abs. Drain Current (A)=20m
Absolute Max. Power Diss. (W)=250m
I(DSS) Min. (A)=12m
g(fs) Min. (S) Trans. conduct.=3.0m
@V(DS) (V) (Test Condition)=10
Status=Discontinued
Package=TO-92
Military=N

From your link:

-50V max, pinout unknown since I can't read hieroglyphs:


It's like earlier I've fried lot of new power MOSFET samples because found a wrong version of datasheet for VN2222 small MOSFET. Later I've found that 2 of them exist, with different parameters and pinouts!

[jacco vermeulen]

50V : 2SK127
80V : 2SK127A

[Wavebourn]

Originally posted by jacco vermeulen
50V : 2SK127
80V : 2SK127A

And one of them is P, another is N?

By the way, I've found today 2 datasheets both from the same Fairchild, for PN5134. According to one document it is PNP, according to another one it is NPN.

According to my quick test, it is NPN.

[Spiny]

Originally posted by Wavebourn


From your link:

-50V max, pinout unknown since I can't read hieroglyphs:

This translates as
1,Drain
2,Gate
3,Source

[Wavebourn]

Originally posted by Spiny


This translates as
1,Drain
2,Gate
3,Source

Thanks a lot Spiny!

[jacco vermeulen]

More fun in Nipponese, number 3 reads Sosu.

(i'd think a wanderer of the smooth harmony path would read some hieroglyphics)