Video: Basics of a Summing Amplifier using an Op Amp

[w2aew]

Following along the lines of Dave's excellent video #600 which gave an overview of the basics of op amps, here's a short tutorial on summing amplifier configurations with op amps:

[electronics man]

Brilliant video, very informative thanks

[w2aew]

Brilliant video, very informative thanks

I'm glad you found it useful! 

While I stated it in the video, I maybe should have stated a little stronger that understanding the basic operation of op amps, as shown in Dave's #600 video or in my video on the topic from last year, is a pre-requisite for understanding this video.

Thanks again for watching!

[Witention]

I've been trying to get my head around "current-mode" op amps (as opposed to "voltage mode"). They seem interesting in that, in a typical configuration (according to a TI app note), bandwidth reduction is only a function of Rf, not the total gain. But I'm not clear on how an op amp can be sensitive to current on its inputs while maintaining a decent approximation of an ideal op amp (i.e., where zero current flows into/out of the inputs).

[w2aew]

I've been trying to get my head around "current-mode" op amps (as opposed to "voltage mode"). They seem interesting in that, in a typical configuration (according to a TI app note), bandwidth reduction is only a function of Rf, not the total gain. But I'm not clear on how an op amp can be sensitive to current on its inputs while maintaining a decent approximation of an ideal op amp (i.e., where zero current flows into/out of the inputs).

The simple answer is - they don't.  Current feedback op amps are different in design, and thus don't follow the same rule that the inputs (at least the inverting input) don't draw current.