Device for supplying pressure to an actuation unit of a motor vehicle braking system and method for controlling said device

A device for supplying pressure to an actuation unit of a vehicle brake system, in particular to a vehicle brake system of the 'brake-by-wire' type, comprising a pneumatic motor-and-pump assembly with a pump and a motor driving the pump, wherein the motor-and-pump assembly is controlled by an electronic control unit depending on a pressure level or pressure difference in a pneumatic brake booster of the actuation unit, with the pressure level in a chamber or a difference in pressure between two chambers of the brake booster being detected by means of a sensor. In order to maintain the availability of the service brake function as high as possible and to obtain a maximum possible redundancy, the control unit, used to control the motor-and-pump assembly comprises a logic module and a power module, which are arranged separately of each other.