Dynamic Characteristics: noise

[ampm]

Dear friends,
Could somebody explain me the meaning of the "Noise" term in the 6723/6733 AO boards specification?
The specification (http://www.ni.com/pdf/manuals/370735d.zip) says

Dynamic Characteristics

Slew rate		0.7 V/µs
Noise		1.0 Vrms, DC to 1 MHz

for 6723

and

Dynamic Characteristics

Slew rate		15 V/µs
Noise		80 µVrms, DC to 1 MHz

for 6733

What is the source of the "Noise"? Is it preseent all the time or just when the output signal changes?
Why is there such a huge difference in  "Noise"  for 6723 and 6733?

Thanks in advance!

[gwd]

- What is the source of the "Noise"?

Thermodynamics.

You might want to start with the (much maligned) Wikipedia. Or do a Google search for "thermal noise."

[ampm]

1.0 V_rms, DC to 1 MHz thermal noise for 6723 ?
That's a little too much for a thermal noise I think.
Thanks anyway.

I hope NI guys will clear the meaning of the "noise" term in specifications.

[gwd]

I didn't see the 1 V.

I expect it is a (serious) misprint.

[David S.]

You're right gwd, it's a goof on our part.  The real spec is 1 mV rms, and we plan to fix the document in its next release.