An inverting amplifier is a type of electronic circuit used to amplify an input signal while inverting its polarity. It is commonly built using an operational amplifier (op-amp) and a few passive components such as resistors. The key feature of an inverting amplifier is that the output signal is 180 degrees out of phase with the input signal.
Characteristics of an inverting amplifier:
Amplification and Inversion: The primary function of an inverting amplifier is to amplify the input signal's voltage while reversing its polarity (inverting it by 180 degrees).
Gain Control: The gain of the inverting amplifier can be easily controlled by selecting appropriate resistor values for R1 and R2. Larger values of R2 relative to R1 result in higher gain.
Frequency Response: The frequency response of the inverting amplifier is dependent on the op-amp's characteristics and the choice of resistors. It can be designed for specific frequency ranges using appropriate components.
Linearity: The inverting amplifier maintains linearity within its operational range, ensuring that the output signal is a faithful representation of the input signal, scaled by the gain factor.
Virtual Ground: Due to the op-amp's high input impedance and the negative feedback provided by the resistor network, a virtual ground is established at the inverting input terminal. This allows for easy referencing of input and output voltages.
Common Usage: Inverting amplifiers find applications in signal processing, audio amplification, instrumentation, and other fields where signal inversion and amplification are needed.
Phase Shift: The output of the inverting amplifier is shifted by 180 degrees compared to the input signal. This phase shift can be advantageous in certain applications, such as in phase-sensitive circuits.
It's important to note that the inverting amplifier has a negative sign in its gain equation, which means that the output signal's amplitude is inverted and scaled by the gain factor. The choice of resistor values also affects the input and output impedance of the circuit, which can impact its interactions with other components in a larger system.