Operational amplifiers (op-amps) amplify signals through the following steps ¹ ²:
- Differential Inputs: Op-amps have two inputs: inverting (-) and non-inverting (+). The op-amp amplifies the difference in voltage between these two inputs (differential input voltage).
- Open-Loop Gain: The op-amp has a very high open-loop gain (AOL), typically over 100,000. This means even a small input voltage can drive the amplifier into saturation.
- Negative Feedback: To control the gain and prevent saturation, negative feedback is applied by connecting a portion of the output voltage to the inverting input.
- Closed-Loop Gain: The feedback network determines the closed-loop gain (ACL), which is much lower than the open-loop gain. The op-amp output adjusts to make the voltage difference between the inputs zero.
- Output: The amplified signal is produced at the output terminal, with the gain determined by the feedback network and the input signal.
