IC voltage regulators are three-terminal devices that provide a constant DC output voltage that is independent of the input voltage, output load current, and temperature. There are three types of IC voltage regulators: IC linear voltage regulators, IC switching voltage regulators, and DC/DC converter chips. IC linear voltage regulators use an active pass element to reduce the input voltage to a regulated output voltage. By contrast, IC switching voltage regulators store energy in an inductor, transformer, or capacitor and then use this storage device to transfer energy from the input to the output in discrete packets over a low-resistance switch. DC/DC converter chips, a third type of IC voltage regulators, also provide a regulated DC voltage output from a different, unregulated input voltage. In addition, DC/DC converters are provide noise isolation regulate power buses. For each type of IC voltage regulator, the output voltage can be fixed or adjusted to a value within a specified range.