Analog Electronics Chapter 1: Operational Amplifiers Explained — Basics to Applications

An amplifier is an electronic device or circuit that increases the power, voltage, or current of an input signal. Amplifiers are a crucial part of many electronic systems, enabling small input signals to be boosted for a variety of applications such as audio devices, communication systems, and instrumentation.

At its core, an amplifier takes a weak input signal and, through its design, produces a stronger output signal while maintaining the characteristics of the input, such as waveform and frequency. This increase in signal strength can be described by the term “gain,” which represents how much an amplifier increases the amplitude of the signal.

The gain of a single amplifier is often insufficient for practical use. To achieve the desired high gain, multiple amplifier stages are coupled together.

An operational amplifier (OPAMP) is a high-gain, direct current (DC) amplifier with differential inputs. It amplifies the difference between two identical but opposite input signals while rejecting common-mode signals (signals that are the same at both inputs). This makes OPAMPs very versatile, as they can amplify both DC and alternating current (AC) signals.

Additionally, OPAMPs can perform various mathematical operations, such as addition, subtraction, differentiation, integration, and even act as buffers or analog-to-digital (A/D) converters. OPAMPs typically require a dual power supply for…