Patent ID: 8344663

Claim:
A circuit arrangement for controlling at least one light source, comprising: a photodetector arranged to detect light from a first and a second light source; an amplifier coupled to an output of the photodetector; a sampling circuit coupled to an output of the amplifier; a control unit, which comprises a first filter having an input coupled to the sampling circuit and an output coupled to a first and a second output of the control unit; a first power-supply source, having a control input coupled to the first output of the control unit and which is adapted for controlling at least one parameter of the first light source; and a second power-supply source, having a control input coupled to the second output of the control unit and which is adapted for controlling at least one parameter of the second light source, wherein the sampling circuit comprises a transmission gate, wherein the first filter comprises an integrator, wherein the integrator comprises a further amplifier, a capacitor and a switch, wherein the switch and the capacitor are connected in a parallel circuit, wherein an input of the further amplifier is connected to the sampling circuit and to an output of the further amplifier via the parallel circuit, and wherein the output of the further amplifier forms an output of the integrator.