5volt

5 volt, commonly written as 5V, refers to a potential difference of five volts. The volt is the SI unit of electric potential, and 5V is a widely used nominal operating voltage in electronics, particularly for digital logic and power supply circuits. It is the baseline in many consumer and embedded devices, though some systems run at lower (such as 3.3V) or higher voltages.

In practical use, 5V appears as a power rail or logic level. USB ports deliver a nominal 5V supply to peripherals, and many computer power supplies include 5V rails and a standby 5VSB line. Microcontrollers, sensors, and countless integrated circuits have historically used 5V logic levels (TTL-era and early CMOS devices), though newer generations increasingly adopt lower voltages. USB-C power delivery and other adapters can negotiate higher voltages, but 5V remains a common default or fallback level in many designs.

Generation and regulation of 5V rails are achieved through linear regulators (for example, fixed 5V regulators) or switching regulators (buck converters). Tolerances vary by standard and component quality; for example, USB 2.0 specifies a voltage range typically from 4.75 to 5.25 V. Maintaining a stable 5V supply requires proper decoupling, impedance control, and careful layout to limit noise, ripple, and voltage drop under varying load.

Plans and standards around 5V have evolved with device design, but the 5V rail continues to be a foundational element in many electronic systems, supporting both power delivery and digital signaling across a broad range of applications. See also USB, TTL, CMOS, and power supplies.