Opamp resistor values

Discussion in 'General Electronics Chat' started by nepdeep, Nov 7, 2012.

  1. nepdeep

    Thread Starter Active Member

    Sep 14, 2011
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    Why can we not put 1 ohm or 1 Meg ohm? in the input terminal of the opamps....Does it have something to do with the bias current?
     
  2. crutschow

    Expert

    Mar 14, 2008
    16,209
    4,333
    Do you understand Ohm's law? Too small a resistor and the current becomes too high for a given signal voltage. Too large a resistor will cause a voltage drop (offset) due to the op amp bias current. Thus typical op amp resistor values go from a few kΩ to perhaps a few hundred kΩ. But if you have a very low bias current input op amp such as a MOSFET or JFET type than you can go above a megohm if needed
     
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  3. Audioguru

    AAC Fanatic!

    Dec 20, 2007
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    Opamps do not have "terminals". Train and bus stations have terminals.
    Opamps have inputs and outputs. What are you talking about?

    Are you talking about an inverting or a non-inverting opamp amplifier?
     
  4. nepdeep

    Thread Starter Active Member

    Sep 14, 2011
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    ya and mr cru..explained
     
  5. ScottWang

    Moderator

    Aug 23, 2012
    5,442
    856
    Talk about what you want to do?
    Talk about why you want to use 1MΩ in the input pins of Op Amp?
     
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