A modular system comprising a first component comprising an LED driver and a second component comprising a light engine; - the LED driver comprising: ∘ a switched mode power converter configured to output a supply current; ∘ a first control unit configured to control a switch (220.2) of the switched mode power converter, thereby controlling the supply current; - the light engine comprising: ∘ an LED assembly configured to receive the supply current, the LED assembly comprising a plurality of LEDs or LED groups and one or more switches (280.1-6) arranged in series or in parallel with one or more LEDs or LED groups of the plurality of LEDs of LED groups, and ∘ a second control unit configured to control the one or more switches of the LED assembly, thereby controlling a supply of the supply current to the plurality of LEDs or LED groups of the LED assembly; wherein the first control unit and the second control unit are configured to co-operate and control the supply current and the supply of the supply current to the LED assembly in accordance with a desired illumination characteristic, and characterised in that the first and second control unit are configured to synchronize a switching operation of the switch (220.2) of the switched mode power converter with a switching operation of the one or more switches (280.1-6) of the light engine; wherein the modular system further comprises: - a serial communication link for connecting the first control unit to the second control. - the LED driver comprising: ∘ a switched mode power converter configured to output a supply current; ∘ a first control unit configured to control a switch (220.2) of the switched mode power converter, thereby controlling the supply current; ∘ a switched mode power converter configured to output a supply current; ∘ a first control unit configured to control a switch (220.2) of the switched mode power converter, thereby controlling the supply current; - the light engine comprising: ∘ an LED assembly configured to receive the supply current, the LED assembly comprising a plurality of LEDs or LED groups and one or more switches (280.1-6) arranged in series or in parallel with one or more LEDs or LED groups of the plurality of LEDs of LED groups, and ∘ a second control unit configured to control the one or more switches of the LED assembly, thereby controlling a supply of the supply current to the plurality of LEDs or LED groups of the LED assembly; wherein the first control unit and the second control unit are configured to co-operate and control the supply current and the supply of the supply current to the LED assembly in accordance with a desired illumination characteristic, and characterised in that the first and second control unit are configured to synchronize a switching operation of the switch (220.2) of the switched mode power converter with a switching operation of the one or more switches (280.1-6) of the light engine; wherein the modular system further comprises: ∘ an LED assembly configured to receive the supply current, the LED assembly comprising a plurality of LEDs or LED groups and one or more switches (280.1-6) arranged in series or in parallel with one or more LEDs or LED groups of the plurality of LEDs of LED groups, and ∘ a second control unit configured to control the one or more switches of the LED assembly, thereby controlling a supply of the supply current to the plurality of LEDs or LED groups of the LED assembly; wherein the first control unit and the second control unit are configured to co-operate and control the supply current and the supply of the supply current to the LED assembly in accordance with a desired illumination characteristic, and characterised in that the first and second control unit are configured to synchronize a switching operation of the switch (220.2) of the switched mode power converter with a switching operation of the one or more switches (280.1-6) of the light engine; wherein the modular system further comprises: - a serial communication link for connecting the first control unit to the second control.