A modular system comprising a first component comprising an LED driver, a second component comprising a light engine and a third component comprising an interface module, the light engine comprising a plurality of LEDs or LED groups; the interface module comprising: - an input terminal (715.1,715.2) for connecting to an output terminal of the LED driver; - an output terminal (715.4, 715.5) for connecting to an input terminal of the light engine; - a switch assembly comprising one or more switches for controlling a supply current of the LED driver, the supply current being received via the input terminal and provided to the light engine via the output terminal; - a control unit having an input terminal for receiving a set point representing a desired illumination characteristic of the light engine, the control unit further having a processing unit for processing the set point and determining control signals for the switch assembly, the LED driver comprising: ∘ a switched mode power converter (750.1) configured to output the supply current; ∘ an LED driver control unit configured to control a switch of the switched mode power converter, thereby controlling the supply current; characterised in that the control unit and the LED driver control unit are configured to co-operate and control the supply current and the supply of the supply current to the light engine in accordance with the desired illumination characteristic, and wherein the control unit and the LED driver control unit are configured to synchronize a switching operation of the switch of the switched mode power converter with a switching operation of the one or more switches of the switch assembly of the interface module and wherein the LED driver control unit is configured to control the LED driver to provide a current pulse to synchronize the switching operation of the switch of the switched mode power converter with the switching operation of the one or more switches of the switch assembly of the interface module. - an input terminal (715.1,715.2) for connecting to an output terminal of the LED driver; - an output terminal (715.4, 715.5) for connecting to an input terminal of the light engine; - a switch assembly comprising one or more switches for controlling a supply current of the LED driver, the supply current being received via the input terminal and provided to the light engine via the output terminal; - a control unit having an input terminal for receiving a set point representing a desired illumination characteristic of the light engine, the control unit further having a processing unit for processing the set point and determining control signals for the switch assembly, the LED driver comprising: ∘ a switched mode power converter (750.1) configured to output the supply current; ∘ an LED driver control unit configured to control a switch of the switched mode power converter, thereby controlling the supply current; characterised in that the control unit and the LED driver control unit are configured to co-operate and control the supply current and the supply of the supply current to the light engine in accordance with the desired illumination characteristic, and wherein the control unit and the LED driver control unit are configured to synchronize a switching operation of the switch of the switched mode power converter with a switching operation of the one or more switches of the switch assembly of the interface module and wherein the LED driver control unit is configured to control the LED driver to provide a current pulse to synchronize the switching operation of the switch of the switched mode power converter with the switching operation of the one or more switches of the switch assembly of the interface module. ∘ a switched mode power converter (750.1) configured to output the supply current; ∘ an LED driver control unit configured to control a switch of the switched mode power converter, thereby controlling the supply current; characterised in that the control unit and the LED driver control unit are configured to co-operate and control the supply current and the supply of the supply current to the light engine in accordance with the desired illumination characteristic, and wherein the control unit and the LED driver control unit are configured to synchronize a switching operation of the switch of the switched mode power converter with a switching operation of the one or more switches of the switch assembly of the interface module and wherein the LED driver control unit is configured to control the LED driver to provide a current pulse to synchronize the switching operation of the switch of the switched mode power converter with the switching operation of the one or more switches of the switch assembly of the interface module.