Common Mode Gain and Differential Gain (Amplifiers #5)

What is common mode gain and differential gain in an amplifier and why are these important? What is the common mode rejection ratio?

Aaron Danner is a professor in the Department of Electrical and Computer Engineering at the National University of Singapore.

Video filmed and edited by Cheryl Lim.
@randomcheryl

[comeflywithme]

one of the best EE teachers out there!

[narendradc]

Excellent video. You are a good teacher. do you mind showing a lab experiment on CMRR and Differential using 50Hz sine wave please?

[jimh]

Also, since you have already covered two types of gain - inherent gain and circuit derived gain, which gain are you talking about? So, if I have a non-inverting amplifier *configuration* with gain of 2, does this mean the differential gain = 2? I'm going to assume here that the differential gain you are talking about is the inherent (very large) gain of the op amp.

Also I am going to assume that the non-inverting amplifier is *not* a differential amplifier since it technically only has a single voltage input- the other input being derived from the feedback loop from the output.

[caleb]

lmao ok, so we are just going to assume that a negative half of the differential voltage magically divides itself, flips polarity, and goes in the input? say you have a two wires coming out of a microphone, what does the practical connection to the opamp inputs look like?

[bomberman]

There are still ten hidden videos? Are you unveiling the rest soon? Thanks, these are great.

[jimh]

To be clear- my understanding is that ALL operational amplifiers are differential amplifiers. What you talk about of "differential" amplifier is actually a "differential amplifier *configuration* "?