A non-inverting amplifier is an electronic circuit configuration used to amplify an input signal while maintaining the same polarity. In other words, the output signal is "in phase" with the input signal, and it's not inverted as it would be in an inverting amplifier configuration.
The basic non-inverting amplifier circuit consists of an operational amplifier (op-amp) and two resistors: one connected between the inverting (-) input of the op-amp and the output, and the other connected between the inverting input and the ground (or a reference voltage). The input signal is applied to the non-inverting (+) input of the op-amp.
Here's a simplified schematic of a non-inverting amplifier:
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+Vin -- R1 --+-- R2 -- Output
|
GND
The voltage gain (A_v) of a non-inverting amplifier can be calculated using the following formula:
=
1
+
2
1
A
v
=1+
R1
R2
Where:
A
v
is the voltage gain of the amplifier.
1
R1 is the resistance connected between the inverting input and the output of the op-amp.
2
R2 is the resistance connected between the inverting input and the ground.
The term
2
1
R1
R2
is often referred to as the gain factor. The gain factor determines how much the input signal is amplified. The "1" in the formula represents the unity gain, which ensures that the signal is not inverted.
Keep in mind a few important points:
The actual voltage gain will depend on the specific resistor values you use.
To ensure proper operation, the open-loop gain of the operational amplifier should be much larger than the desired closed-loop gain of the amplifier circuit.
The input signal should stay within the operational range of the op-amp to avoid distortion or clipping.
Remember that real-world operational amplifiers might have limitations due to factors like bandwidth, input impedance, and output impedance, so it's important to consider those aspects when designing and using non-inverting amplifiers.