The operational amplifier can also be used to construct a non-inverting amplifier with the circuit indicated below. The input signal is applied to the positive or non-inverting input terminal of the operational amplifier, and a portion of the output signal is fed back to the negative input terminal. Analysis of the circuit is performed by relating the voltage at V2 to both the input voltage Vin and the output voltage Vo.
The output is applied back to the inverting (-) input through the feedback circuit (closed loop) formed by the input resistor R1 and the feedback resistor R2. This creates ve feedback as follows. Resistors R1 and R2 form a voltage-divider circuit, which reduces Vo and connects the reduced voltage V2 to the inverting input.