Amateur Extra: Op Amp Output Impedance

What is the typical output impedance of an integrated circuit op-amp? [E7G15]

A. Very low
B. Very high
C. 100 ohms
D. 1000 ohms

A A. Very low output impedance is a property of an IC op-amp.   In an ideal case, it would be zero.  But of course that’s never possible.

In reality, the behavior of an op-amp depends on the circuit that its in, and it can be used in many different types of circuits (see image above.)

The reason for the low impedance, is so that the voltage gain that is output by the device acts on the rest of the circuit, and not the op amp itself.  If the voltage output had to contend with a high impedance across the output terminals, The power would go there, instead of actually being output.

More information: http://www.learningaboutelectronics.com/Articles/Why-does-an-op-amp-need-a-high-input-impedance-and-a-low-output-impedance

(image: https://commons.wikimedia.org/wiki/File:Op-amp_circuits.jpg)

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