Analog circuit in the context of Operational amplifier

Microelectronics is a subfield of electronics. As the name suggests, microelectronics relates to the study and manufacture (or microfabrication) of very small electronic designs and components. Usually, but not always, this means micrometre-scale or smaller. These devices are typically made from semiconductor materials. Many components of a normal electronic design are available in a microelectronic equivalent. These include transistors, capacitors, inductors, resistors, diodes and (naturally) insulators and conductors can all be found in microelectronic devices. Unique wiring techniques such as wire bonding are also often used in microelectronics because of the unusually small size of the components, leads and pads. This technique requires specialized equipment and is expensive.

Digital integrated circuits (ICs) consist of billions of transistors, resistors, diodes, and capacitors. Analog circuits commonly contain resistors and capacitors as well. Inductors are used in some high frequency analog circuits, but tend to occupy larger chip area due to their lower reactance at low frequencies. Gyrators can replace them in many applications.

A linear integrated circuit or analog chip is a set of miniature electronic analog circuits formed on a single piece of semiconductor material.

A mixed-signal integrated circuit is any integrated circuit that has both analog circuits and digital circuits on a single semiconductor die. Their usage has grown dramatically with the increased use of cell phones, telecommunications, portable electronics, and automobiles with electronics and digital sensors.

An operational amplifier (often op amp or opamp) is a DC-coupled electronic amplifier with a differential input, a (usually) single-ended output voltage, and an extremely high gain. Its name comes from its original use of performing mathematical operations in analog computers. The voltage-feedback opamp (the focus of this article) amplifies the voltage difference between its two inputs, while the less common current-feedback op amp amplifies the current between its two inputs.

By using negative feedback, an op amp circuit's characteristics (e.g. its gain, input and output impedance, bandwidth, and functionality) can be determined by external components and have little dependence on temperature coefficients or engineering tolerance in the op amp itself. This flexibility has made the op amp a popular building block in analog circuits.

Electronic hardware consists of interconnected electronic components which perform analog or logic operations on received and locally stored information to produce as output or store resulting new information or to provide control for output actuator mechanisms.

Electronic hardware can range from individual chips/circuits to distributed information processing systems. Well designed electronic hardware is composed of hierarchies of functional modules which inter-communicate via precisely defined interfaces.

An electronic piano is a keyboard instrument designed to simulate the timbre of a piano (and sometimes a harpsichord or an organ) using analog circuitry.

"Electronic Piano" was also the trade name used for Wurlitzer's popular line of electric pianos, which were produced from the 1950s to the 1980s, although this was not actually what is now commonly known as an electronic piano. Electronic pianos work similarly to analog synthesizers in that they generate their tones through oscillators, whereas electric pianos are mechanical, their sound being electrified by a pickup and then amplified through an internal or external amplifier.

SiGe (/ˈsɪɡiː/ or /ˈsaɪdʒiː/), or silicon–germanium, is an alloy with any molar ratio of silicon and germanium, i.e. with a molecular formula of the form Si_1−xGe_x. It is commonly used as a semiconductor material in integrated circuits (ICs) for heterojunction bipolar transistors or as a strain-inducing layer for CMOS transistors. IBM introduced the technology into mainstream manufacturing in 1989. This relatively new technology offers opportunities in mixed-signal circuit and analog circuit IC design and manufacture. SiGe is also used as a thermoelectric material for high-temperature applications (>700 K).

A differential amplifier is a type of electronic amplifier that amplifies the difference between two input voltages but suppresses any voltage common to the two inputs. It is an analog circuit with two inputs ${\displaystyle V_{\text{in}}^{-}}$ and ${\displaystyle V_{\text{in}}^{+}}$ and one output ${\displaystyle V_{\text{out}}}$, in which the output is ideally proportional to the difference between the two voltages:

where ${\displaystyle A}$ is the gain of the amplifier.