# operational amplifier > high-gain voltage amplifier with a differential input **Wikidata**: [Q178947](https://www.wikidata.org/wiki/Q178947) **Wikipedia**: [English](https://en.wikipedia.org/wiki/Operational_amplifier) **Source**: https://4ort.xyz/entity/operational-amplifier ## Summary An operational amplifier (op-amp) is a high-gain voltage amplifier with a differential input. It's a versatile electronic component used in countless applications to amplify signals, perform mathematical operations, and create various circuit functions. ## Key Facts - An operational amplifier is classified as both an electronic amplifier and an integrated circuit (IC) - The term originated with these circuits being used to perform mathematical operations in analog computers - The μA709, introduced in 1965, was one of the early general-purpose operational amplifiers - The μA741 model, created in 1968, became one of the most famous and widely used op-amps - Operational amplifiers come in various configurations including single (LME49710), dual (LM358, RC4558), and quad (TL074) packages - They have aliases including op-amp, ampli-op, amplificadores operacionales, and amplificateur operationnel - Operational amplifiers are classified under Dewey Decimal Classification 621.395 - The Soviet Union produced their own series of operational amplifiers including the 1408 series and 140 series (introduced in 1970) - Specialized types include current-feedback operational amplifiers and operational transconductance amplifiers ## FAQs ### Q: What is the primary function of an operational amplifier? A: An operational amplifier is designed to amplify voltage signals with very high gain and has a differential input that responds to the difference between two input voltages while ignoring any voltage common to both inputs. ### Q: What are the most commonly used operational amplifier models? A: The most widely recognized models include the LM741, LM358, LM258, μA741, μA709, and the NE5532 which is specifically designed for audio applications. Each model has different characteristics suited for various applications. ### Q: How have operational amplifiers evolved over time? A: Operational amplifiers have evolved from early general-purpose models in the 1960s like the μA709 (1965) and μA741 (1968) to specialized versions for audio, low-power applications, and high-fidelity uses, with manufacturers continuing to develop improved variants with better noise performance, bandwidth, and precision. ## Why It Matters Operational amplifiers are fundamental building blocks in modern electronics, forming the core of countless circuits from signal processing systems to audio equipment and control systems. Their versatility, reliability, and performance characteristics have made them indispensable in electronic design since their introduction in the 1960s. Without operational amplifiers, many modern technologies including audio equipment, medical instrumentation, communication systems, and industrial automation would not function as they do today. Their differential input design provides excellent noise rejection, while their high gain and flexible configuration options enable engineers to create complex functions with simple, standardized components. ## Notable For - High voltage gain capability, typically ranging from 10,000 to 1,000,000 (or 80-120 dB) - Differential input design that responds to the difference between two input signals while rejecting common-mode signals - Versatile circuit configurations that can perform mathematical operations like addition, subtraction, integration, and differentiation - Remarkable longevity in design, with the classic μA741 architecture remaining relevant decades after its introduction - Numerous specialized variants including current-feedback amplifiers, operational transconductance amplifiers, and FET-input amplifiers ## Body ### Classification and Types Operational amplifiers fall under the broader category of electronic amplifiers and are specifically implemented as integrated circuits. They exist in various configurations including single, dual, and quad packages to accommodate different space and functionality requirements. The class includes specialized types such as current-feedback operational amplifiers, which use current rather than voltage as the feedback signal, and operational transconductance amplifiers, which convert input voltage to output current. ### Notable Models and Series The history of operational amplifiers includes several significant models and series: - The μA709, introduced in 1965, was an early general-purpose operational amplifier - The iconic μA741 model was created in 1968 and became one of the most widely recognized op-amps - The LM358 and LM258 are low-power dual operational amplifiers - The LM4562 is a dual operational amplifier specifically designed for high-fidelity and professional audio applications - The LME49710 is a single operational amplifier IC introduced in 2000 - The TL07x series (introduced in September 1978) includes single (TL071), dual (TL072), and quad (TL074) versions - The NE5532 is specifically designed for audio applications ### Soviet Development The Soviet Union developed its own series of operational amplifiers: - The 1408 series integrated circuits was a Soviet series of operational amplifiers - The 140 series integrated circuits was introduced in 1970 and represented Soviet operational amplifier circuits - The 553 series integrated circuits was another Soviet series of operational amplifier circuits - The 574 series integrated circuits featured FET-input operational amplifiers ### Technical Characteristics Operational amplifiers are characterized by: - Very high voltage gain (typically 10,000 to 1,000,000) - High input impedance - Low output impedance - Wide bandwidth (varies by model, from low-frequency to high-speed types) - Low distortion (particularly in audio-specific models like the NE5532 and LM4562) - Power supply rejection ratio to minimize noise from power supply fluctuations ### Applications Due to their versatile nature, operational amplifiers are used in: - Audio equipment (preamplifiers, equalizers, mixers) - Signal conditioning and filtering - Analog computation - Instrumentation amplifiers - Voltage regulators - Oscillators and waveform generators - Active filters - Comparators - Sample-and-hold circuits ## References 1. Integrated Authority File 2. [Nuovo soggettario](https://thes.bncf.firenze.sbn.it/termine.php?id=21798) 3. [Source](https://www.electronics-tutorials.ws/opamp/opamp_6.html) 4. Nuovo soggettario 5. Freebase Data Dumps. 2013 6. Quora 7. National Library of Israel 8. [OpenAlex](https://docs.openalex.org/download-snapshot/snapshot-data-format)