A driver for driving an LED uses PWM in a sequence of the periods. The driver has a modulo counter, that is reset after each period. The driver has a first adder for combining the count value with a quantity indicative of a shift of the LED's control pulse relative to the start of the period; a second adder for combining the count value with a width quantity indicative of a width of the control pulse; and a logic gate receiving the MSBs at the outputs of the adders and supplying the control pulse.