Image Number 2 for United States Patent #7791405.
A voltage controller for controlling an output voltage to a predetermined value. The voltage controller has a first terminal configured to connect a supply voltage, a second terminal configured to output the output voltage, a control voltage generating unit configured to provide a control voltage, and a control transistor. The control transistor is connected as a series controller between the first terminal and the second terminal. The control voltage can be applied to the control terminal of the control transistor, wherein the output voltage is controlled in a manner dependent on the supply voltage and the control voltage. Furthermore, an offset voltage is superposed on the control voltage.