Re: low noise amplifier for high impedance source

On 16 Oct 2006 15:53:38 -0700,
Winfield Hill <Winfield_member@xxxxxxxxxxx> wrote
in Msg. <eh12hi0187i@xxxxxxxxxxxxxxx>

For example, a classic 2n4392 has en = 3nV and Crss = 3pF.
Compare this to a bf862 with en = 0.9nV and Crss = 1.9pF.
Ooops!! Actually, that's a bad example, contrary to Mother
Nature, as well as Murphy's Law, because the Philips bf862
JFET is far, far better than it should be! :-)

I don't have the 4329 data***, but note that the BF862's noise is
spec'd at 100kHz. But the BF862 does seem to have a rather large gm for
its low capacitance. When you say "contrary to Mother nature" it sounds
as if you meant to imply "contrary to the laws of physics" which would
imply "faked data***". Did you mean to say that? Personally, I
wouldn't put anything past Philips and especially NXP.

robert
.