7805 voltage regulator, detailed information about how a 7805 works and reference links 7800 series voltage regulators - description & circuits. Datasheets Voltage Regulator Databook (Historical 1980), National Semiconductor LM78xx / LM340 (positive), Texas Instruments (TI acquired National Semiconductor) L78xx (positive), STMicroelectronics LM79xx (negative), Texas Instruments L79xx (negative), STMicroelectronics Linear integrated circuits Voltage regulation de:Spannungsregler#Typenbezeichnungen_78xx