Suppose I have an OpAmp (a behavioral model ;-) that has a gm=1 driving a load resistor R, thus the voltage gain=R
Thus am I correct in assuming that the input-referred noise from the load resistor, R, is so low as to be ignorable, thus I can avoid having to use a noiseless resistor model as the load?
Am I correct that, in this case...
VN_input-referred = 0.13/sqrt(R) nV/rt-Hz ?
For a 100K load, thus gain=100K, VN = 411e-6 nV/rt-Hz ?? ...Jim Thompson
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| James E.Thompson | mens |
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The 1-Hz noise of a 60.4 ohm resistor is 1 nV and 16.5 pA, so your numbers don't appear to be right.
Cheers
Phil Hobbs
(and the 1-Hz shot noise of 3 uA is 1 pA)
Looks OK to me. It's just the open-source noise voltage of the load resistor divided by the gain. Utterly negligible, even at Arizona room temperatures. ;-)
Jeroen Belleman
Indeed ;-) ...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I'm looking for work... see my website.
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