Can you compare the input resistances for inverting and non-inverting amplifers?

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  • Steven
    Lv 7
    1 month ago

    We might assume you are talking about classic single OP-AMP circuits but you didn't say that. The input of an inverting op-amp circuit is one side of the feedback network so the input impedance is limited by that network. The positive input can be nothing but a FET gate impedance which is almost an open circuit. But it is not difficult for other circuits to feature negative inputs with extremely high input impedance. A single transistor common emitter/source amplifier is an inverting amplifier.

  • 1 month ago

    The input impedance of an Op amp is very High, Usually several Meg Ohms. They are the bases of a differential pair of transistors or FET's.

    If you look up the data sheet of the OpAmp it will tell you the Impedance.

    Inverting and non inverting are the same op amp just wired differently, therefore dependent on the circuit wiring.

  • qrk
    Lv 7
    1 month ago

    You can, but that's probably not the answer you are seeking.

    Post a schematic of what you are asking about as an "amplifier" can have many forms.

  • 1 month ago

    Sure you can compare them, you can compare just about any two objects/items. If you are referring to common op-amp circuits in the inverting and non-inverting configurations, then in general the non-inverting amp has a very high input impedance and the inverting amp has an input impedance equal to the input series resistor.

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  • 1 month ago

    Both are close to same.

  • 1 month ago

    In determining which is which, it doesn't work. Input impedance is generally the same for any differential amp

  • Dixon
    Lv 7
    1 month ago

    You can compare the Taj Mahal with a banana

  • 1 month ago

    Yes.

    But for any practical approach, in either case the input resistance is either high enough not to matter, or you need to quantify the specific circuit and all the components used.

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