Patent ID: 8872498

Claim:
A DC/DC voltage converter for a motor vehicle having a battery providing a battery voltage, the DC/DC voltage converter comprising: a step-up converter for converting the battery voltage to an intermediate voltage, with the intermediate voltage being greater than or equal to the battery voltage, said step-up converter configured for open-loop control, at least in one operating mode, of the intermediate voltage in dependence on the battery voltage at a value which is not equal to the battery voltage; and a step-down converter for receiving the intermediate voltage output from said step-up converter and for regulating of an output voltage being less than or equal to the intermediate voltage; said step-up converter including a switch and a control circuit configured to open and close said switch to step-up said battery voltage when the battery voltage is less than a first predetermined value, and to permanently open said switch when the battery voltage is greater than the first predetermined value.