Abstract: The invention relates to a method for producing a supply voltage, in particular for digital circuits, in a motor vehicle from a relatively high input voltage of more than 12 volts, in particular from a vehicle power supply system voltage of 42 volts, in which an intermediate voltage at a level between the vehicle power supply system voltage and the supply voltage is produced from the vehicle power supply system voltage in a normal mode by means of a DC/DC converter (5), and the supply voltage is produced from the intermediate voltage by means of at least one linear regulator (9, 9′, 9″), in which the DC/DC converter (5) is switched off and is bridged by means of a bypass circuit (11) in a parking mode, so that the supply voltage is produced directly by the at least one linear regulator (9, 9′, 9″), and to a voltage supply circuit for this purpose.

Abstract: The invention relates to a method for producing a supply voltage, in particular for digital circuits, in a motor vehicle from a relatively high input voltage of more than 12 volts, in particular from a vehicle power supply system voltage of 42 volts, in which an intermediate voltage at a level between the vehicle power supply system voltage and the supply voltage is produced from the vehicle power supply system voltage in a normal mode by means of a DC/DC converter (5), and the supply voltage is produced from the intermediate voltage by means of at least one linear regulator (9, 9′, 9″), in which the DC/DC converter (5) is switched off and is bridged by means of a bypass circuit (11) in a parking mode, so that the supply voltage is produced directly by the at least one linear regulator (9, 9′, 9″), and to a voltage supply circuit for this purpose.

Abstract: An electrical system architecture for a motor vehicle is described. The system architecture has a generator outputting a high AC voltage and at least one low AC voltage and a voltage processing unit for generating a high DC voltage from the high AC voltage. A coupling device is provided for coupling the low AC voltage to the high DC voltage. A high voltage line is provided, which is fed by the coupling device, and to which the high DC voltage with the superimposed low AC voltage is applied.