JFET complementary pair

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Yes Mirlo,

...."But Japanese (Toshiba) JFETs rule.

2sk170/2sj74"....

I used these in the Magnet PR9R folded cascode preamp which was a runaway success in Thailand, was their most successful preamp ever and has been a flagship product for 10 years. Even rebadged as a US brand along with the 300F power amp, rated TAS Golden Ear award.

Yes, matched K170/J74 cut it!

Cheers,
Greg
 
Yes, 2SK170/2SJ74 rule !
If you're going to use a fully symetrical jfet input, you might consider the attached configuration. This showed excellent constant current in real world and reduces part count heavily.
Don't forget to cascode them, the sj74 has max vds of 25v.

Mike
 

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mirlo

Japanese CPUs??

For microcontrollers, OK.

Not PCs

But Japanese (Toshiba) JFETs rule.

2sk170/2sj74
-------------------------------------------------
whats so special about cpus americans had a standard there
x86 that protected them, intel is a lousy technology in cpus other
american companies like Zilog and Motorola kicked their butts with
better processors and better standards that didnt take off because of intel's standard in the marketplace that still gives them
a free ride with whatever crap they come up with, at the time
americans had fallen 6 years behind in technology and there was
no hope in sight then the american goverment took protecting
measures to save the industry and the japs pulled out once there
was no more market for them there especially in the microprocessor business
 
2N5401 2N5551
are two good and useful complementary TO92 transistors
They take 150 V and 625 mW

but,
these are bipolar, BJT and not JFET


To find very good matching complementary N-JFETs and P-JFETs
is impossible, as far as I know.
Same goes for N- and P- MOSFETs.

Not even bipolar NPN and PNP are ever perfectly matched complementary.
Nevertheless you can use them as pairs
with good result in most cases.
 
If you're looking for high transconductance, consider the following:

* 2N6550 (100mAtyp, .3<Vgs<3, 25<Gfs<150mS, Goss<150uS).
* Interfet U290-U291 (500mAmin, 4<Vgs<10, 350mStyp, 100pF, .7nV/sqHz).
* Interfet IF1801 (30mAmin, .35<Vgs<2, >50mS, 100pF, .5nV/sqHz).
* Interfet IF3602 (Dual, 30mAmin, .35<Vgs<3, 750mStyp, 300pF, .3nV/sqHz).
 
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