Browse Definitions :
Definition

voltage reference

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

SearchNetworking
  • network security

    Network security encompasses all the steps taken to protect the integrity of a computer network and the data within it.

  • cloud-native network function (CNF)

    A cloud-native network function (CNF) is a service that performs network duties in software, as opposed to purpose-built hardware.

  • Wi-Fi 6E

    Wi-Fi 6E is one variant of the 802.11ax standard.

SearchSecurity
  • incident response

    Incident response is an organized approach to addressing and managing the aftermath of a security breach or cyberattack, also ...

  • MICR (magnetic ink character recognition)

    MICR (magnetic ink character recognition) is a technology invented in the 1950s that's used to verify the legitimacy or ...

  • What is cybersecurity?

    Cybersecurity is the protection of internet-connected systems such as hardware, software and data from cyberthreats.

SearchCIO
  • privacy compliance

    Privacy compliance is a company's accordance with established personal information protection guidelines, specifications or ...

  • contingent workforce

    A contingent workforce is a labor pool whose members are hired by an organization on an on-demand basis.

  • product development (new product development -- NPD)

    Product development, also called new product management, is a series of steps that includes the conceptualization, design, ...

SearchHRSoftware
  • talent acquisition

    Talent acquisition is the strategic process employers use to analyze their long-term talent needs in the context of business ...

  • employee retention

    Employee retention is the organizational goal of keeping productive and talented workers and reducing turnover by fostering a ...

  • hybrid work model

    A hybrid work model is a workforce structure that includes employees who work remotely and those who work on site, in a company's...

SearchCustomerExperience
  • digital marketing

    Digital marketing is a general term for any effort by a company to connect with customers through electronic technology.

  • hockey stick growth

    Hockey stick growth is a growth pattern in a line chart that shows a sudden and extremely rapid growth after a long period of ...

  • Salesforce Trailhead

    Salesforce Trailhead is a series of online tutorials that coach beginner and intermediate developers who need to learn how to ...

Close