A circuit arrangement for an optical monitoring system comprises a driver circuit (DRV) which is configured to generate at least one driving signal for driving the light source (LS). A detector terminal (DT) is arranged for receiving a detector current (Id) from an optical detector (OD). A gain stage (GS) is connected at its input side to the driver circuit (DRV) for receiving the driving signal and generates a noise signal depending on the driving signal. A processing unit (PU) is configured to generate an output signal (SO) depending on the detector current (Id) and the noise signal.
