A multi-channel light emitting diode, led, driver, as well as a corresponding method, led based lighting device and a computer program product

A method of operating a multi-channel Light Emitting Diode, LED, driver, the multi-channel LED driver, comprising:

• a plurality of LED channels, wherein each of said plurality of LED channels comprises at least one LED for emitting light, and a switch connected in series with said at least one LED for enabling/disabling said at least one LED, and a storage capacitor connected in parallel over said at least one LED and said switch;
• a Direct Current, DC, power supply arranged for providing DC power to each of said plurality of LED channels;
• a plurality of charge switches, wherein each of said plurality of charge switches is electrically connected to a respective storage capacitor of a respective LED channel of said plurality of LED channels, wherein each of said plurality of charge switches is arranged for enabling charging, from said provided DC power, said respective storage capacitor,
• a controller configured for controlling said plurality of charge switches as a Time Division power demultiplexer such that said DC power is distributed over said storage capacitors of said plurality of LED channels,
• wherein said controller is further arranged for:
• measuring headroom voltages of the at least one LED in the corresponding LED channels;
• determining duty cycles for each of the charge switches based on the measured headroom voltages,
• wherein said controller is arranged for controlling said plurality of charge switches as a Time Division power demultiplexer such that a sum of duty cycles for controlling said charge switches is at least equal to one,
• determining that a lowest measured headroom voltage of said measured headroom voltages is below the reference headroom voltage;
• and
• requesting said DC power supply to increase its output DC power, wherein the method comprises:
• controlling, by said controller, said plurality of charge switches as a Time Division power demultiplexer such that said DC power is distributed over said storage capacitors of said plurality of LED channels.