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Question 8.1: An operational amplifier operating with negative feedback pr......

An operational amplifier operating with negative feedback produces an output voltage of 2 V when supplied with an input of 400 μV. Determine the value of closed-loop voltage gain.

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Now:

A_{V(CL)}  =  \frac{V_{OUT}}{V_{IN}}

Thus:

A_{\mathrm{V(CL)}}={\frac{2}{400\times10^{-6}}}={\frac{2\times10^{6}}{400}}=5,000

Expressed in decibels (rather than as a ratio) this is:

A_{V(CL)}  =  20\log_{10}(5,000) = 20 × 3.7 = 74 dB

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