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need to understand impedence concept

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i read a line in book but didnt understand,
"An operational amplifier, or op-amp, is a very high gain differential amplifier with
high input impedance and low output impedance"

what does it mean high input impedence and low output impedence.??

does it means input resistance and output resistance.???
 

These concepts r related in context to load-Source relationship & power transfer.
 

It's a complicated subject but basically it's telling you the op-amp places very little loading (high impedance) on the thing driving it and it's output is capable of being more heavily loaded (low impedance). The actual impedance depends on the device and the feedback paths around it.

Brian.
 

Impedance is AC resistance.
The input impedance and input resistance of an opamp is 1M ohms to billions of ohms.
The output impedance of an opamp is 0.01 ohms at DC and low frequencies to 75 ohms at higher frequencies. Its output resistance is 75 ohms.
 

Impedance is a combination of a real part and an imaginair part. The real part is resistance, the imaginair part is reactance. Reactance is the AC resistance of a capacitor or an inductor. So reactance can be positive (inductance) or negative ) capacitance
|Z| is the absolute value of impedance in Ohm, split up the notation is Z = ( Rs + jX ) If +jX is equal to -jX then the result is the real part and this is called resonance.
If you use the correct name in google, that is ; impedance instead of impedence you will find all the information you need : https://en.wikipedia.org/wiki/Electrical_impedance
A good book about opamps: opamps for everyone, free download from TI: https://www.google.nl/url?sa=t&rct=...QxYdkL4XemccjuNYQ&sig2=2am6d1PtpoFvxbxupN7tag
 
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