Semiconductor & Electronics Technical Glossary

A piezoelectric resonator that generates a precise frequency when an electric field is applied across its surfaces, exploiting the mechanical resonance of the crystal structure. Quartz crystals are the fundamental timing element in oscillators used across aerospace, medical, automotive, and telecommunications applications. Key parameters include frequency, load capacitance, equivalent series resistance (ESR), and frequency tolerance expressed in parts per million (PPM).

SourcesIEEE Xplore

An oscillator that uses a temperature-sensing and compensation network to maintain frequency stability across a defined temperature range, typically expressed in parts per million (PPM). TCXOs offer significantly better stability than standard crystal oscillators without the power consumption of an oven-controlled design. Commonly used in portable communications equipment, GPS receivers, and instrumentation.

SourcesIEEE Xplore

An oscillator housed in a temperature-controlled oven that maintains the crystal at a constant elevated temperature, delivering the highest frequency stability available in a crystal-based timing device. OCXOs are used in applications requiring extreme precision such as atomic clock references, telecommunications synchronization, and metrology equipment. Stability specifications are typically in the parts per billion (PPB) range.

SourcesIEEE Xplore

An oscillator whose output frequency can be tuned across a defined range by varying an applied input voltage. VCXOs are used in phase-locked loop (PLL) circuits, clock recovery systems, and applications requiring frequency synchronization. The tuning range is expressed as pull range in PPM per volt.

SourcesIEEE Xplore

A silicon-based timing device that uses micro-electromechanical systems (MEMS) technology as a frequency reference, replacing the quartz crystal resonator with a microfabricated silicon structure. MEMS oscillators offer advantages in shock and vibration resistance and are manufactured using standard semiconductor processes. They are increasingly used in consumer electronics, IoT devices, and some industrial applications as an alternative to quartz-based timing devices.

SourcesIEEE Xplore

The unit used to express frequency stability, tolerance, and aging in oscillators and crystals. One PPM represents one millionth of the nominal frequency — for example, 1 PPM at 10 MHz equals a deviation of 10 Hz. Lower PPM values indicate tighter frequency control and are required in precision applications such as GPS, telecommunications infrastructure, and test and measurement equipment.

SourcesNIST Time and Frequency Division

The gradual, irreversible change in oscillator output frequency over time due to internal material changes including stress relief in the crystal mounting structure, contamination of the resonator surface, and changes in the oscillator circuit components. Aging is typically specified in PPM per year and is a critical parameter for long-life applications in aerospace and defense systems where recalibration intervals must be minimized.

SourcesIEEE Xplore

A measure of the short-term frequency stability of an oscillator, expressed as the ratio of noise power in a 1 Hz bandwidth at a specified offset from the carrier frequency to the total signal power, measured in dBc/Hz. Phase noise is critical in radar, communications, and test and measurement applications where it directly affects system dynamic range and signal resolution.

SourcesIEEE Xplore

The degree to which an oscillator maintains its nominal output frequency over time, temperature, supply voltage variations, and load changes. Frequency stability is the aggregate specification that encompasses temperature stability, aging, vibration sensitivity, and supply voltage sensitivity — and is the primary parameter by which frequency control products are selected for demanding applications.

SourcesIEEE Xplore

The capacitance value specified by the crystal manufacturer that the oscillator circuit must present to the crystal for it to oscillate at its specified nominal frequency. Incorrect load capacitance in the oscillator circuit design results in frequency offset from the nominal value. Load capacitance is a critical parameter that must be correctly matched during hardware design.

SourcesIEEE Xplore — Crystals and Frequency Management

A wide-bandgap semiconductor material with properties that enable operation at higher voltages, temperatures, and frequencies than conventional silicon. Gallium Nitride (GaN) devices are used in RF power amplifiers for 5G base stations and radar systems, power electronics for electric vehicle (EV) inverters, and defense electronics including electronic warfare systems. GaN on silicon carbide (GaN-on-SiC) substrates is standard in high-power RF applications; GaN on silicon (GaN-on-Si) is used in cost-sensitive power conversion applications.

SourcesIEEE Xplore — Introduction to GaN Properties and Applications

A wide-bandgap semiconductor material used in high-voltage, high-temperature power electronics applications. Silicon Carbide (SiC) devices including MOSFETs and Schottky diodes enable higher switching frequencies, lower conduction losses, and higher operating temperatures than silicon equivalents. Primary applications include electric vehicle (EV) traction inverters, industrial motor drives, solar inverters, and onboard charging systems.

SourcesIEEE Xplore — GaN and SiC Power Devices Review

An integrated circuit that processes continuous electrical signals, performing functions such as amplification, filtering, signal conditioning, voltage regulation, and analog-to-digital conversion. Analog ICs are present in virtually every electronic system as the interface between real-world physical signals and digital processing. Key suppliers include Texas Instruments (TI), Analog Devices, and ON Semiconductor.

SourcesWikipedia — Analog Signal Processing

An integrated circuit that contains both analog and digital circuit blocks on a single die, enabling signal processing that spans both domains. Mixed-signal ICs include analog-to-digital converters (ADCs), digital-to-analog converters (DACs), and system-on-chip (SoC) devices that integrate analog front ends with digital signal processors. Mixed-signal design requires specialized expertise in both analog and digital circuit design and layout.

SourcesWikipedia — Mixed-Signal Integrated Circuit

The complete hierarchical list of all components, subassemblies, raw materials, and quantities required to manufacture an electronic product. The Bill of Materials (BOM) is the central document in hardware product development and procurement — specifying approved manufacturers, part numbers, quantities, and reference designators for every component. Being specified on a customer's BOM is the primary commercial objective in semiconductor and electronic components sales, representing a committed design win.

SourcesGlobal Electronics Association (formerly IPC) — IPC Standards

The individual semiconductor chip cut from a processed silicon wafer before packaging. A single wafer typically yields hundreds to thousands of individual die depending on the die size and wafer diameter. Die can be sold unpackaged as bare die or known good die (KGD) for applications such as multi-chip modules (MCM) and chip-on-board (COB) assemblies used in aerospace and medical electronics where space and weight are critical.

SourcesWikipedia — Die (Integrated Circuit)

A thin, circular slice of semiconductor material — typically silicon, but also silicon carbide (SiC), gallium arsenide (GaAs), or gallium nitride (GaN) — on which integrated circuits are fabricated using photolithographic processes. Wafer diameters range from 150mm (6 inch) for compound semiconductors to 300mm (12 inch) for leading-edge silicon logic and memory. Wafer size directly affects manufacturing cost per die.

SourcesWikipedia — Wafer (Electronics)

The manufacturing plant where semiconductor wafers are processed through hundreds of steps of deposition, lithography, etching, and doping to create integrated circuits. Fabs represent capital investments of $10 billion or more for leading-edge nodes and are the primary subject of the CHIPS and Science Act domestic manufacturing incentives. The term fab is also used as a verb — to fab a chip means to manufacture it.

SourcesWikipedia — Semiconductor Fabrication PlantCHIPS and Science Act

A semiconductor company that manufactures chips designed by other companies, providing fabrication services without designing its own products. Leading foundries include TSMC (Taiwan Semiconductor Manufacturing Company), Samsung Foundry, and GlobalFoundries. The foundry model has enabled the growth of fabless semiconductor companies by separating chip design from manufacturing.

SourcesWikipedia — Semiconductor Fabrication Plant

A semiconductor company business model in which the company designs integrated circuits but outsources all manufacturing to a foundry partner. Fabless companies include Qualcomm, NVIDIA, AMD, and thousands of smaller IC design firms. The fabless model reduces capital requirements and allows companies to focus resources on design and intellectual property development rather than manufacturing infrastructure.

SourcesWikipedia — Fabless Manufacturing

The automotive qualification standard for passive electronic components including resistors, capacitors, inductors, and crystals, developed by the Automotive Electronics Council (AEC). Components must pass a defined series of stress tests covering temperature cycling, humidity, mechanical shock, and vibration to achieve AEC-Q200 qualification. Procurement managers at automotive Tier 1 suppliers and OEMs require AEC-Q200 qualification as a prerequisite for approved vendor list (AVL) inclusion.

SourcesJEDEC

The automotive qualification standard for active semiconductor devices including integrated circuits, developed by the Automotive Electronics Council (AEC). AEC-Q100 defines a series of failure mechanism-based stress tests that ICs must pass to be qualified for use in automotive applications. It is the active device complement to AEC-Q200 for passive components.

SourcesJEDEC

The United States military performance specification for quartz crystal units used in defense electronics. MIL-PRF-3098 defines the performance requirements, test methods, and quality assurance provisions for crystals intended for military and aerospace applications. Manufacturers must demonstrate qualification to this specification to supply crystals for defense programs, and components are listed on the Qualified Products List (QPL).

SourcesEverySpec

The test standard for microcircuits used in military and aerospace applications, defining test methods for mechanical, electrical, and environmental characterization of semiconductor devices. MIL-STD-883 test methods are referenced in procurement specifications for defense electronics and are required for components used in flight hardware, weapon systems, and other high-reliability military applications.

SourcesEverySpec

The international standard for the safety and performance of medical electrical equipment, published by the International Electrotechnical Commission (IEC). IEC 60601 compliance is required for electronic equipment used in medical environments and defines requirements for electrical safety, electromagnetic compatibility (EMC), and essential performance. Component manufacturers supplying the medical electronics market must understand how their products affect their customers' ability to achieve IEC 60601 compliance.

SourcesIEC

The global standards organization for the microelectronics industry, formally known as the Joint Electron Device Engineering Council. JEDEC publishes standards covering memory interfaces, component qualification (including the AEC-Q series for automotive applications), package outlines, and reliability test methods. JEDEC standards are widely referenced in procurement specifications and component datasheets across the semiconductor industry.

SourcesJEDEC

The European Union directive restricting the use of specific hazardous materials — including lead, mercury, cadmium, and hexavalent chromium — in electrical and electronic equipment. Restriction of Hazardous Substances (RoHS) compliance is mandatory for electronic products sold in the EU and has been adopted as a de facto global standard by most major OEMs regardless of geography. Component datasheets must explicitly state RoHS compliance status.

SourcesIEC

The European Union regulation on the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH), which governs the use of chemical substances in products sold in the EU. REACH requires manufacturers and importers to identify and manage risks associated with substances of very high concern (SVHC) present in their products above defined threshold concentrations. Electronic component manufacturers must maintain REACH compliance documentation as part of their customer-facing regulatory package.

SourcesIEC

The United States federal regulations administered by the Department of State that control the export and import of defense-related articles, services, and technical data listed on the United States Munitions List (USML). International Traffic in Arms Regulations (ITAR) compliance is required for semiconductor and electronic components companies supplying products for military platforms, weapon systems, and certain space applications. Export of ITAR-controlled technical data to foreign nationals — including employees on US soil — requires specific authorization.

SourcesUS State Department DDTC

The United States regulations governing the export of commercial and dual-use technology, including certain semiconductor products, administered by the Bureau of Industry and Security (BIS) within the Department of Commerce. Export Administration Regulations (EAR) apply to a broader range of products than ITAR and use the Export Control Classification Number (ECCN) system to categorize items. Advanced semiconductors and semiconductor manufacturing equipment are subject to EAR controls that have been significantly tightened since 2022.

SourcesBureau of Industry and Security

The list of pre-qualified suppliers from which a manufacturer is authorized to source specific components. Approved Vendor List (AVL) inclusion is the procurement milestone that follows a successful design-in and qualification process — it represents the formal authorization to supply a component into production. Being added to a customer's AVL is one of the most significant commercial outcomes in electronic components sales, as it creates ongoing, repeatable revenue tied to production volumes.

SourcesGlobal Electronics Association (formerly IPC) — IPC Standards

The elapsed time between placement of a purchase order and physical delivery of components to the customer's facility. Lead times for electronic components range from stock (same day) to 52 weeks or more for allocated or custom components. Lead time visibility became a critical procurement and marketing parameter following the global semiconductor shortage of 2020 to 2023, and is now a key consideration in approved vendor selection alongside price and technical performance.

SourcesSEMI

A formal notification issued by a component manufacturer announcing that a specific product will be discontinued and will no longer be available for purchase after a defined last-order date. End of Life (EOL) notifications trigger last-time-buy decisions by procurement teams, obsolescence management programs, and redesign activity by engineering teams seeking pin-compatible replacement components. EOL management is a significant ongoing challenge in long-life applications such as aerospace, defense, and industrial systems.

SourcesJEDEC

A procurement action taken when a component reaches End of Life (EOL) status, in which buyers purchase sufficient stock to cover all anticipated future production needs before the manufacturer's final ship date. Last time buy quantities must account for remaining product life, yield losses, field service requirements, and safety stock — making accurate demand forecasting critical. Failure to execute an adequate last time buy can result in production stoppages and costly redesigns years after the original EOL notification.

SourcesJEDEC

Contract manufacturers that produce electronic assemblies and complete products on behalf of original equipment manufacturer (OEM) customers, providing services including PCB assembly, system integration, testing, and supply chain management. Leading EMS providers include Foxconn, Jabil, Flex, and Celestica. EMS companies are significant buyers of electronic components and represent an important channel for component manufacturers, as EMS procurement teams often have significant influence over component selection alongside the OEM design team.

SourcesGlobal Electronics Association (formerly IPC) — IPC Standards

The United States federal law — formally Public Law 117-167, signed by President Biden on August 9, 2022 — that authorizes approximately $52.7 billion in direct funding and $24 billion in investment tax credits to incentivize domestic semiconductor manufacturing, research, and workforce development. Passed by the Senate 64 to 33 on July 27, 2022 and the House 243 to 187 on July 28, 2022, the Act also restricts recipients from expanding advanced chip manufacturing in countries of concern for ten years. The National Institute of Standards and Technology (NIST) administers the program through the CHIPS for America office. The Act represents the largest single government investment in domestic semiconductor manufacturing in United States history and is reshaping global supply chain strategy for semiconductor manufacturers, equipment suppliers, and materials companies worldwide.

SourcesPublic Law 117-167full enacted textCHIPS for America program at NIST