Hard NJFET nut to crack!

[kkrafs]

Hi folks!

Im trying to find the data for the TBF0006LT1
N-JFET transistor! Doing searches on the net
gives one hit whos innacessible. :sad:

Anyone perhaps having a old Motorola
data book on FET transistors???

Its a sot23 with marking 6CM wich also
dont give any hits in the sot marking tables.

 

[bcarso]

That's obscure. How do you know it is a JFET to begin with?

It doesn't sound like any Moto discrete I ever heard of, but maybe it was. There is no sign of anything like that part number on the On Semi website that I could see.

In any event, if it is a JFET it should be easy to establish the approximate parameters by a few measurements. Determine which lead is the gate via a little forward current using the diode test function on a DMM. The other two leads are generally interchangeable. Call one the source and tie the gate and it to common, and measure the current into the drain with a 5V or thereabouts power supply to determine Idss. Drive the gate separately through a 100k or so to avoid destructive screwups and leave the source at common and the drain at 5V. With another supply feed a negative adjustable voltage to the gate through the resistor and see what it takes to have the drain current go to ~zero. That cutoff voltage will tell you a lot as well.

 

[jhaible]

[quote author="kkrafs"]Hi folks!

Im trying to find the data for the TBF0006LT1
N-JFET transistor! Doing searches on the net
gives one hit whos innacessible. :sad:

Anyone perhaps having a old Motorola
data book on FET transistors???
[/quote]

I've checked Motorola Small Signal Transitor data books from 1983,
1989 and 1991.

Nothing. Not *anything* starting with "TBF" either.

JH.

 

[bcarso]

Could be a manufacturer's internal part number. Where did the idea come from that it was Motorola in the first place?

 

[kkrafs]

I know its a JFET since when i bought them from a surplus
store i had the box they came in ( tape reel).
Unfortunately i think the tapereel was trown out
during a move to another town, many years ago.

From the tape i have the manufacturer and the number.

Doing a search at:
http://www.partminer.com/pagedetail/5543/17

Will give Motorola, they have datasheets but i have
never been able to get it from partminer, they refuse to
send registration passwords for some unknown reason!

 

[bcarso]

Measure them. Between Ron, Idss, and pinchoff voltage it will likely be easy to guess at the process. There aren't that many different types of JFETs.