Question 8.2: An operational amplifier has an input resistance of 2 MΩ Det......

Electronic Circuits Fundamentals and Applications [1001472]

An operational amplifier has an input resistance of 2 MΩ Determine the input current when an input voltage of 5 mV is present.

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Now:

R_{IN}  =  \frac{V_{IN}}{I_{IN}}

thus

I_{IN}  =  \frac{V_{IN}}{R_{IN}}  =  \frac{5  \times  10^{-3}}{2  \times  10^{6}}  =  2.5  \times  10^{-9}  A  =  2.5  nA

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