The present document relates to providing power for driving SSL devices. A power converter converts a varying input voltage to supply an output voltage to a SSL device in series with a current source. The power converter comprises one or more capacitors; a plurality of switches to couple the capacitors in a plurality of configurations. A control unit operates the power converter in a plurality of operational modes providing a corresponding plurality of different conversion ratios between the input/output voltages. The operational modes comprise a first phase and a second phase, during which the capacitors are differently arranged. The control unit controls the switches to alternate between the phases at a commutation cycle rate. The control unit sets the operational mode based on the varying input voltage.