A non-inverting amplifier is an electronic circuit used in analog electronics to amplify an input signal. Its purpose is to increase the amplitude of an input signal while maintaining the same polarity (i.e., not inverting the signal's phase). In other words, the output voltage of the non-inverting amplifier is in phase with the input voltage.
The basic configuration of a non-inverting amplifier consists of an operational amplifier (op-amp) and two resistors. The op-amp is a high-gain voltage amplifier with two input terminals (inverting and non-inverting) and one output terminal.
Here's a simple explanation of how a non-inverting amplifier works and its purpose:
Amplification: The primary purpose of the non-inverting amplifier is to provide signal amplification. When an input signal is applied to the non-inverting input terminal of the op-amp, it is amplified by a factor known as the voltage gain (Av). The voltage gain is determined by the ratio of the feedback resistor (Rf) to the input resistor (Rin). The gain formula for the non-inverting amplifier is Av = 1 + (Rf / Rin).
No phase inversion: Unlike the inverting amplifier, where the output signal is inverted (180 degrees out of phase) with respect to the input signal, the non-inverting amplifier maintains the same phase as the input signal. This property is useful in applications where maintaining the input signal's phase relationship with the output is crucial.
High input impedance: The non-inverting amplifier has a high input impedance, meaning it does not draw much current from the input source. This property makes it suitable for interfacing with high-impedance signal sources without loading or affecting the original signal.
Stable configuration: The non-inverting amplifier is inherently more stable than the inverting amplifier due to its positive feedback nature. It is less prone to oscillations and typically exhibits better noise performance.
Non-inverting amplifiers find applications in various electronic systems, such as audio amplifiers, signal conditioning circuits, sensors, active filters, and precision measurement equipment. They are widely used in electronics because of their simplicity, stability, and the ability to provide voltage gain without phase inversion.