Questions regarding 3.3V level signals, level-shifting, and circuits.

is a common voltage supply rail used in Computing and Consumer devices. This is down from the last defacto standard of power supplies. The lower voltage is derived from the need to save on power, and is often found in newer .

Other typical supplies rails are and , though circuits using even lower voltages of 2.5v, 1.8v, and 1.2v are becoming increasingly common, especially in mobile devices, for the same reason.