Inverting and Non-inverting Amplifiers An inverting amplifier takes an input voltage and reverses its direction to output a voltage with the same amplitu...
An inverting amplifier takes an input voltage and reverses its direction to output a voltage with the same amplitude but with the opposite polarity. It achieves this by employing a comparator circuit that compares the input and output voltages. If the input voltage is higher than the output voltage, the comparator generates a signal that drives the output transistor to amplify the input. Conversely, if the input voltage is lower than the output voltage, the output transistor is driven off, effectively filtering out the input signal.
The non-inverting amplifier, on the other hand, takes an input voltage and directly outputs it to the output without inverting it. It achieves this by using a operational amplifier (op-amp), which acts as a virtual reference voltage. The op-amp compares the input and output voltages and adjusts its internal voltage to match the input voltage. If the input voltage is higher than the output voltage, the op-amp sets the output voltage to a higher value. Conversely, if the input voltage is lower than the output voltage, the op-amp sets the output voltage to a lower value.
Examples:
An inverting amplifier can be used to amplify a signal from a microphone, with the amplified signal being sent to a loudspeaker.
A non-inverting amplifier can be used in audio applications to prevent the audio signal from being inverted (which can cause distortion).
Key Differences:
| Feature | Inverting Amplifier | Non-inverting Amplifier |
|---|---|---|
| Direction of output voltage | Reverse | Same |
| Polarity of output voltage | Negative | Positive |
| Use case | Amplifying a signal from a microphone | Preventing the audio signal from being inverted |