In the non inverting configuration the phase of the input signal is the same of the output signal. The gain is determined by the feedback resistance. The basic circuit of a non-inverting operational amplifier application is shown in figure bellow. The following formula is used to determine the gain.
Formula:
Gain:
G = 1 + (R2 / R1)
Where:
G is the gain
R1 and R2 are the resistances in ohm (Ω)
Formula:
Voltage gain:
Vout = Vin x [ 1+ (R2 / R1) ]
Where:
Vout is the output voltage in volts (V)
Vin is the input voltage in volts (V)
R1 and R2 are the resistances in ohm (Ω)
Note: the output voltage cannot exceed the power supply voltage.
Application example:
In the circuit shown in figure above, R2 is a 100 kΩ resistor and R1 is a 10 kΩ resistor. Determine the gain.
Data:
R1 = 10 kΩ
R2 = 100 kΩ
G = ?
Applying formula:
G = 1 + [ (100 x 103) / (10 x 103) ]
G = 1 + 10
G = 11
