Difference Amplifier

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Determine Vout. Need to process two signal using math function as difference use this circuit. Difference signal almost as first method in sensor and instrument amplifier.

First, you determine the voltage at the noninverting input by using the voltage divider relation (again, assume that no current enters the inputs):

Next, apply Kirchhoff’s current junction law to the inverting input (I1 = I2):

Using rule 4 (V+ = V−), substitute the V+ term in for V− in the last equation to get