Voltage references are electronic devices that provide a fixed output voltage. They provide a constant voltage regardless of external factors. This includes the load on the device, temperature or fluctuations in the power supply. Learn more in our Complete Guide to Voltage References.Voltage references have different characteristics depending on their purpose. Voltage references used in laboratory applications are designed to have extremely high precision and accuracy, whereas those used as regulators for computer power supplies are much cheaper but less precise.There are many different kinds of voltage references, generally categorised by type, tolerance, rated voltage, reference voltage and rated current. The most common tolerances are ±2%, ±1% and ±0.5%, but voltage references are available even up to ±40%.Voltage reference ICs come in a standard semiconductor package, such as PDIP, SO, SOIC and SOT-23. The pin count may also be combined with the package type, for example SO-8.Types of voltage referencesTwo-terminal shunt voltage referenceThree-terminal series voltage referenceBand-gap voltage referenceLow noise voltage referenceMicropower voltage referenceWhat are voltage references used for?Voltage references can be used for a variety of different precision measurement and control systems such as power supplies in personal computers and analogue-to-digital converters. They are also used in scientific applications and in medical equipment where voltage variations need to be tested regularly. Voltage references are also used in battery-powered devices.