Hi tt,
10mV is not that difficult to achieve if you get it indirectly.
Imagine that you a 50ohm output impedance is desired. (as with most signal
generators) Now produce a 1Vpeak-to-peak output, pass it through a voltage
divider (say.. 10k on top, and 10ohm to ground) and at that midpoint, you
have a 1mV signal and the output impedance is parallel combination of the
two resistances to AC ground. (10 // (10k + 50) if the original signal
generator had 50 ohm output). Then put a 40 ohm in series with the center
tap and, there you have it.. a 50ohm impedance signal generator with a 1mV
signal output and a relatively easy to create 1V signal input.
These kinds of attenuators are used all of the time when testing high
gain circuits. I don't see any reason why it couldn't help you out here..
unless you want to go so low that you are greatly affected by thermal noise.
)
This does limit the upper range of your signal generator (you would need
1000V for a 1V output), so perhaps voltages this low may require a special
mode to be used. Depending on the frequency ranges you are looking at, a
relay could switch between the modes fairly easily.
I hope that helps a bit.
Best Regards,
Adam Kumpf
[email protected]
http://web.mit.edu/kumpf/www/kumpf-projects.html