A transceiver unit for a user station of a serial bus system. The transceiver unit has a first connection for receiving a transmit signal from a communication control unit, a transmitter for transmitting the transmit signal to a bus of the bus system, a receiver for receiving the signal from the bus, the receiver generating a digital receive signal from the signal received from the bus, a second connection for transmitting the digital receive signal to the communication control unit and for receiving an additional signal from the communication control unit, and an operating mode switching block for evaluating the receive signal output by the receiver and a signal received at the second connection by the communication control unit. The operating mode switching block switches the transmitter and/or the receiver into one of at least two different operating modes as a function of a result of the evaluation.