Introduction to Johnson-Nyquist Noise (Amplifiers #13)

Let's work some example problems related to Johnson-Nyquist noise and discuss practical implications for circuit design.
Aaron Danner is a professor in the Department of Electrical and Computer Engineering at the National University of Singapore.
danner.group
Video filmed and edited by Cheryl Lim.
@randomcheryl

[@AndrewKiethBoggs]

Thanks for the concise derivation of the maximum available noise power. Such a simple explanation that clears up so much!

[@comeflywithme1694]

Thank you for posting this video series. Love every one of them.

[@captainoneaye]

Thank you soooo much for these videos about noise. I have always been confused about noise and how it works and I simply didn't find any sources to explain it well. Watching your videos, I understood it immediately and can now go forward to create much more precise models for my circuits. Thank you Prof. Danner!

[@SergiuCosminViorel]

PERFECTLY PRACTICAL!
One thing missing there, though. The maximum power that can be transfered, should use not the 20 kcps, but the maximum bandwidth, you said Terra-cps. I do not know if only Terra-cps, and am not trying to determine, am limitting my activities to what my activities should be. Anyway, consider the maximum bandwidth, possibly up to frequencies associated to the electrons themselves. That gives the maximum power transfer. Should be much greater. Make partition of thermal energy between nucleous and electrons, and the maximum transfer shoul go up to half the thermal of the electrons, which is huge, compared to what you presented here.

[@garageelectronics4649]

Hi Aaron, Could you suggest good analog design books where we can find all these? And also i would like to know what books you follow. Thank you.

[@Roe124]

this video is SO good
thanks for the upload!

[@Mr2Xri]

You have an amazing way to explain things.

[@ninjarider2941]

An example of thermal noise reduction: many oscilloscopes have a 20 MHz low pass filter to reduce noise that is introduced by the instrument. This is helpful for measuring small signals that have low frequencies.

[@bomberman0023]

I had to look up the term "negative frequency" as this was not a concept I was familiar with. It may be too much of a digression to get into the math behind it for this topic, but I didn't recall hearing it before.

[@gregwmanning]

What is temperature? How do the electrons/atoms know it is "hot" (or cold) and know they have to move around alot and make noise or increase resistance?

[@omerdeger1743]

If I am wrong, one can correct me, It is highly appreciated.
For your question, I think you are looking what is going on in a reverse way. An electron does not need to know whether it is hot or not. Being hot or not is defined by us, comparing the temperature. Remember, temperature is defined as average kinetic energy. So in terms of our definition, when we said something is hot, it means its average kinetic energy is high, which actually means it moves much faster. So does electrons, which yields rise in noise

[@gregwmanning]

@@omerdeger1743 That make alot of sense, Thanks Greg