about offset voltage of op-amp

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urian

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hi,there
when we model the input offset voltage of op-amp with single-end input on inverting input,we always model it as a voltage source driving the noninverting input.
my question is that why we dont model it as a vltage source driving the inverting input?

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urian
 


Of course, you can do it. The result will be exactly the same. Start a calculation and compare the results.
 

    urian

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@LvW
Exactly... the result would be same

@urian
The input offset voltage that you would insert in your circuit would be at inverting node of opamp.
So your equation will be (0-VIO)/R1 = (VIO-VOUT)/R2
this has the same effect as having a VIO( input offset voltage at non inverting terminal)->concept of virtual ground...
 

    urian

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thx,guys
i thought they may be different before.now you clarify it.
Yes,it may be the habit of famous authors to put the input offset voltage at the noninverting node.
 

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