The usual PNP pass transistor has been replaced by a PMOS pass element. Because the PMOS pass element behaves as a low-value resistor, the dropout voltage is very low, typically 57 mV at 50 mA of load current (TPS79030), and is directly proportional to the load current. The quiescent current is ultralow (17 A typically) and is stable over the entire range of output load current (0 mA to 50 mA). Intended for use in portable systems such as laptops and cellular phones, the ultralow-dropout voltage feature and ultralowpower operation result in a significant increase in system battery operating life.