Dropout Voltage (or Current) is defined as the minimum voltage drop required across the regulator to maintain output voltage at which a magnetically operated device that will release to its deenergized position. The Dropout Voltage is insufficient to maintain the device in an energised state, and important to have a low dropout voltage for increased efficiency and minimal heat dissipation. Linear voltage regulators require inputs which are higher than the rated output voltages.
Related Definitions in the Project: The Electrical Engineering