A single-stage AC-DC single-inductor multiple-output (SIMO) light emitting diode (LED) driver comprising: an AC-DC rectifier circuit ; a DC-DC converter that receives the output of the rectifier circuit and passes it through an input switching circuit (s a , s b ) of said DC-DC converter and an inductor of said DC-DC converter to an output of the driver, said DC-DC converter circuit including a control circuit which produces a control signal that causes the input switching circuit to alternately open and close; an output switching circuit (S 1 , ..., S N ) that sequentially connects the output of the inductor to respective individual strings of LEDs in round robin fashion; and comparator circuits that each compare the current in a respective LED string to a reference, characterized in that : the comparator circuits set the period of time during which the output switching circuit connects the inductor to each respective string of LEDs based on the comparison so as to maintain a current level in each respective LED string ; wherein the outputs of the comparator circuits are multiplexed into a single signal y by a multiplexer , and wherein the control circuit for the input switching circuit further includes a first divider (R1, R2) for providing a portion of the output of the rectifier circuit, a squaring circuit for squaring the portion of the output of the rectifier circuit to produce a signal x, and a second divider circuit for dividing the y signal by the x signal to produce the control signal for the switching circuit so that the effect of a change in input AC to the rectifier circuit has a reduced effect on the DC operating point of the driver. an AC-DC rectifier circuit ; a DC-DC converter that receives the output of the rectifier circuit and passes it through an input switching circuit (s a , s b ) of said DC-DC converter and an inductor of said DC-DC converter to an output of the driver, said DC-DC converter circuit including a control circuit which produces a control signal that causes the input switching circuit to alternately open and close; an output switching circuit (S 1 , ..., S N ) that sequentially connects the output of the inductor to respective individual strings of LEDs in round robin fashion; and comparator circuits that each compare the current in a respective LED string to a reference, the comparator circuits set the period of time during which the output switching circuit connects the inductor to each respective string of LEDs based on the comparison so as to maintain a current level in each respective LED string ; wherein the outputs of the comparator circuits are multiplexed into a single signal y by a multiplexer , and wherein the control circuit for the input switching circuit further includes a first divider (R1, R2) for providing a portion of the output of the rectifier circuit, a squaring circuit for squaring the portion of the output of the rectifier circuit to produce a signal x, and a second divider circuit for dividing the y signal by the x signal to produce the control signal for the switching circuit so that the effect of a change in input AC to the rectifier circuit has a reduced effect on the DC operating point of the driver. <EOS>