jfet

Reminder that the J105 exists, and is still in production.

Offhand, a modest 200mW dissipation gets you, say, 100mA at 2V, which could be coupled to a 50 ohm load (or even 10-20 ohms with matching, or even less in a cascode). It would fall somewhere around 200mS transconductance, so against a load of 20mS, you'd get a quite reasonable gain of 10. And with max 160pF drain capacitance (not counting Miller effect..), bandwidth out to

Not bad, for a junction too big for its own (thermal) good... :)

The noise plot isn't very specific (nor very high Id), but it looks at least as quiet as other parts...

The audio guys seem to like 'em. 1/f knee is usefully low.

Tim

X-Chapters? Did I order too soon?

Someplace you have to take a ratio of the noise to the signal.

Too much setup to do very often.

I want to make a little die-cast box with some banana jacks, that will measure anything I give it, and that I can chuck in a tub till the next time I need to measure noise. I have a lot of little gizmos like that, and they save a bunch of time.

;)

My Mum used to say that "laziness is the father of invention". My Dad was one of the most energetic characters I've ever known, but the trait was obviously recessive.

Cheers

Phil "More of a Mycroft than a Sherlock" Hobbs

Not super fast, though. The BF862 has an f_max of about 750 MHz, and that starts to matter pretty far down in frequency when you're building efficient bootstraps. (The one in the QL-01 has a calculated gain of about 0.9997 out to about a megahertz, and the performance measurements seem to bear this out.)

Once I have the noise tester going, I'll get a few, thanks.

Cheers

Phil Hobbs

Great, you'll like it. Lots of measured info -- they really did their homework!

Nope, it's supplementary (another book), as far as I know. :) The student and teacher workbooks I think are awaiting, too..?

Tim