Browse Definitions:
Definition

voltage reference

Contributor(s): Stan Gibilisco

A voltage reference is an electronic component or circuit that produces a constant DC (direct-current) output voltage regardless of variations in external conditions such as temperature, barometric pressure, humidity, current demand, or the passage of time.

The earliest voltage references were electrochemical components, notably the Weston standard cell and the lead-acid cell. The Weston cell contained two electrodes immersed in a solution of cadmium sulfate, and produced a predictable 1.018 volts DC at room temperature. A lead-acid cell, still used in automotive and emergency-power applications today, contains a solution of sulfuric acid and produces 2.1 volts DC at room temperature. The main problem with all electrochemical cells and batteries, when forced to serve as voltage references, lies in the fact that the output voltage varies depending on the current demand. In general, when the cell or battery must deliver more current, its output voltage goes down because of its own internal resistance.

Simple contemporary voltage references rely on semiconductor components known as Zener diodes. When a certain minimum amount of current passes through a Zener diode, a predictable voltage develops across it, and this voltage (called the avalanche voltage or Zener voltage) remains the same as the current continues to increase. The exact voltage depends on the design of the device, and can range from around 1 volt to more than 100 volts. More sophisticated voltage references take advantage of the properties of junctions between specific semiconductor materials, comparing multiples of the voltages between those materials to the voltage developed across a conventional semiconductor diode. These devices are called bandgap voltage references.

Voltage references are used in the power supplies of precision electronic equipment of all kinds, particularly systems of the sort whose performance is greatly affected by small changes in the voltage applied to them. Personal computers and peripherals can tolerate a fair amount of voltage fluctuation (up to several percent above or below the nominal value), as can most consumer communications devices. Scientific and medical laboratory equipment can tolerate voltage variations of only a tiny fraction of one percent above or below the nominal value.

This was last updated in July 2012

Continue Reading About voltage reference

Start the conversation

Send me notifications when other members comment.

By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

Please create a username to comment.

-ADS BY GOOGLE

File Extensions and File Formats

Powered by:

SearchCompliance

  • PCAOB (Public Company Accounting Oversight Board)

    The Public Company Accounting Oversight Board (PCAOB) is a Congressionally-established nonprofit that assesses audits of public ...

  • cyborg anthropologist

    A cyborg anthropologist is an individual who studies the interaction between humans and technology, observing how technology can ...

  • RegTech

    RegTech, or regulatory technology, is a term used to describe technology that is used to help streamline the process of ...

SearchSecurity

  • email spam

    Email spam, or junk email, is unsolicited bulk messages sent through email with commercial, fraudulent or malicious intent.

  • distributed denial of service (DDoS) attack

    A distributed denial-of-service attack occurs when an attack originates from multiple computers or devices, usually from multiple...

  • application whitelisting

    Application whitelisting is the practice of identifying applications that have been deemed safe for execution and restricting all...

SearchHealthIT

  • athenahealth Inc.

    Based in Watertown, Mass., athenahealth Inc. is a leading vendor of cloud-based EHRs for small to medium-sized physician ...

  • Affordable Care Act (ACA or Obamacare)

    The Affordable Care Act (ACA) is legislation passed in 2010 that changed how uninsured Americans enroll in and receive healthcare...

  • HIPAA Privacy Rule

    The Standards for Privacy of Individually Identifiable Health Information, commonly known as the HIPAA Privacy Rule, establishes ...

SearchDisasterRecovery

  • disaster recovery as a service (DRaaS)

    One approach to a strong disaster recovery plan is DRaaS, where companies offload data replication and restoration ...

  • data recovery

    Data recovery restores data that has been lost, accidentally deleted, corrupted or made inaccessible. Learn how data recovery ...

  • disaster recovery plan (DRP)

    A company's disaster recovery policy is enhanced with a documented DR plan that formulates strategies, and outlines preparation ...

SearchStorage

  • virtual memory

    Virtual memory is a memory management capability of an OS that allows a computer to compensate for physical memory shortages by ...

  • yottabyte (YB)

    A yottabyte is a measure of theoretical storage capacity and is 2 to the 80th power bytes, or, in decimal, approximately 1,000 ...

  • Kilo, mega, giga, tera, peta, exa, zetta and all that

    Kilo, mega, giga, tera, peta, exa, zetta are among the list of prefixes used to denote the quantity of something, such as a byte ...

SearchSolidStateStorage

  • PCIe SSD (PCIe solid-state drive)

    A PCIe SSD (PCIe solid-state drive) is a high-speed expansion card that attaches a computer to its peripherals.

  • SSD caching

    SSD caching, also known as flash caching, is the temporary storage of data on NAND flash memory chips in a solid-state drive so ...

  • NVDIMM (Non-Volatile Dual In-line Memory Module)

    An NVDIMM (non-volatile dual in-line memory module) is hybrid computer memory that retains data during a service outage.

SearchCloudStorage

  • RESTful API

    A RESTful application program interface breaks down a transaction to create a series of small modules, each of which addresses an...

  • cloud storage infrastructure

    Cloud storage infrastructure is the hardware and software framework that supports the computing requirements of a private or ...

  • Zadara VPSA and ZIOS

    Zadara Storage provides block, file or object storage with varying levels of compute and capacity through its ZIOS and VPSA ...

Close