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LM324: Impedance

Karthik A
Prodigy 130 points

Part Number: LM324

Tool/software:

Where to find open loop input impedance and open loop output impedance of LM324 datasheetLMx24-N, LM2902-N Low-Power, Quad-Operational Amplifiers datasheet (Rev. D) - lm324-n.pdf

  • 0
    TI__Mastermind 30098 points

    Karthik,

    See figure 5-20

    Best regards, Art

  • 0 in reply to Art Kay
    Prodigy 130 points

    Hi Art Kay

    Thanks for the response.,

    could you help me to figure out open loop input impedance.

  • 0 in reply to Karthik A
    Prodigy 130 points

    And the graph attached impedance vs frequency is not in datasheet.

    if possible could you guide me,how to get this data.

  • 0 in reply to Karthik A
    TI__Mastermind 30098 points

    Karthik,

    Sorry, I misread your original post.  You asked for open loop input impedance and I gave you open loop output impedance.  However, the graph that I posted is in the data sheet, so I want to confirm that we are both looking at the same data sheet:  LM324.  If you search that data sheet for figure 5-20 you will find the figure I posed.  If you don't find the figure, than something very strange is happening with what you download vs what I get.  Please double check.

    For open-loop input impedance you should look at the "input capacitance" specification (see below).  For most data sheets this is called "input impedance".  Normally this specification provides the impedance and capacitance on the op amp input.  This is what is provided for this data sheet, it is only called something different.  Note that there really is not a difference between open-loop input impedance and closed-loop input impedance.  Output impedance, on the other hand is substantially different in the open-loop case versus closed loop case.

    Sorry for the miscommunication. I hope this helps.

    Best regards, Art

  • +1 in reply to Art Kay
    Prodigy 130 points

    Hi Art

    Thanks .,

    Ya i was searching in LM324-N, in that data sheet there is no information about impedance.