Re: Low noise IF3601/02 don't meet specs

In the old days - silicon manufacturers used to publish the test setups to
acheive the data *** spec's.

These days there is less information on how the data *** values are
acheived.

Some times the only hint from the data *** is the "recommend values" (not
limits).

If you have some weight..... (meaning.... you are going to purchase
significat volumes) you can lean on the distributors of the InterFET or
InterFET themselves
to get info on how the results are acheived.... No weight (no $$$ ) may
mean no support.


You can't say the FET doesn't meet spec's until you repoduce the mfg'ers
test setup... and even then they may have something special which helps
reduce the noise during testing - that is not documented.


Regards
JG

Hmmm the front page of their data books says

InterFET is big enough to competitively supply over 400 standard

JFET types. Small enough to craft JFETs to your exact specifications.

Big enough to supply national and international leading-edge electronic

manufacturers and laboratories. Small enough for you to talk directly

with the people that engineer and manufacture the product.

Every business has a culture, a way of doing business. Ours isÉ

How we serve each customer is more important than how many

customers we serve.





"Fred Bartoli"
<fred._canxxxel_this_bartoli@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote in
message news:43b558ab$0$21719$626a54ce@xxxxxxxxxxxxxxx
> I've finally got to test some of those huge Interfet jfets for their
> noise.
> Impressive, but...
> they are spec'd at 300pV/rtHz @ 5mA and 100Hz and should get down near
> 260pV
> @ 100kHz.
>
> Well for the IF3601 and both side of the IF3602 dual, I get 400pV/rtHz @
> 5mA, and the noise PSD is almost flat.
>
> I have to rise Id to 20mA (x4) to get almost the low Id noise specs (get
> 290pV/rtHz at 100kHz).
>
> Before I get some other parts, I'd like to know if someone managed to
> obtain
> the figures they claim.
>
> Both samples have the same date code, so it might be just a bad process
> issue... or not.
>
>
> --
> Thanks,
> Fred.
>
>


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