Some JFET thoughts...

[Magnus Danielson]

Hi!

I have been thinking a bit about these JFETs that we tend to use...

First, there are 2N4391's (used in the ASM-1) available from
Temic/Siliconix (http://www.temic.com/ and http://www.siliconix.com/).
I would not be supprised if others makes them aswell, there are three
diffrent packages (including SOT-23) available.

There is also a number of possible improvements over the 2N4391, if
you are willing to trade switch speed for lower resistance and thus
have shorter reset time of the oscillator.

Without much deeper thoughts, I picked out the J105 which has an
rDS(on) of maximum 3 ohm as compared to the 30 ohm of the 2N4391.
There are several other picks that could be interesting for this, but
giving a quick look the the above webpages makes me pick J105.

Also, take a peek at the VCR7N, it could be a interesting thing for
people doing variable resistance stuff with FETs.

Cheers,
Magnus