[sdiy] SMT noise generation?

[John Speth]

>      I've got an analog noise generator design I'm fleshing out, and
hit a
> bit of a wall. I'm reaching out to do a sanity check since my discrete
> engineering expertise is a wee bit rusty. The simple question
> goes: If I have a TO-92 BC547 and replace it with a SOT-23 BC847,
since they
> are the same part and have the same parameters, would that mean they
would
> generate the same amount of noise? Part of me says yes because all the
other
> parameters (Hfe, Vce, Ic, etc) line up, but another part of me says
that
> since it's in a smaller package and may use less material to achieve
those
> properties that there would be less noise. Could anyone clear this up
for me?

I think for a huge majority of silicon that die and packaging are
independent parameters.  The dies are cut and are packaged in whatever
package the manufacturer chooses.  It's the die that makes the noise not
the package (generally speaking).  There might be more to the packaging
that I'm not considering but for a low power transistor, I think it
doesn't matter what package it comes in.

JJS