An inverting amplifier is a basic electronic circuit configuration used to amplify an input signal while inverting its polarity. It consists of an operational amplifier (op-amp) with two external resistors: a feedback resistor (Rf) and an input resistor (Rin). The input signal is applied to the inverting input (-) of the op-amp, and the output is taken from the output terminal.
The basic symbol of an op-amp is as follows:
markdown
Copy code
+ Vcc
|
^
|
|---| Output (Vout)
| |
| |
^
|
- Vinput
The inverting amplifier circuit looks like this:
markdown
Copy code
+ Vcc
|
^ Rf
|-----/\/\--- Output (Vout)
| |
^ |
| |
- Vinput Rin
The gain of the inverting amplifier (Av) can be calculated using the formula:
Av = -Rf / Rin
Where:
Av is the voltage gain of the amplifier.
Rf is the feedback resistor's resistance.
Rin is the input resistor's resistance.
Note that the gain (Av) is negative, indicating the inversion of the input signal's polarity. The magnitude of the gain depends on the ratio of the feedback resistor (Rf) to the input resistor (Rin). By choosing appropriate resistor values, the inverting amplifier can amplify the input signal by a specific factor. Keep in mind that practical considerations, such as the maximum output voltage swing of the op-amp, may limit the achievable gain.