In one embodiment a current source comprises an input (In) for receiving a brightness signal (Sb), and an output (Out) for providing a driving current (Id) for at least one light-emitting diode, LED, wherein the current source (CS) is configured to extract a first and a second current value (idac_high, idac_low) from the brightness signal (Sb), to derive a duty cycle value (Smod) from the brightness signal (Sb) and to modulate the driving current (Id) as a function of the duty cycle value (Smod) in a pulse-width modulation comprising the first and the second current values (idac_high, idac_low). Furthermore, a method for providing a current is described.