Led driving circuit

Abstract

A LED driving circuit (20) is for driving at least two LED segments (22, 24) of different color or color temperature, using an input current which has a current ripple amplitude. The LED driving circuit (20) comprises an input to receive the input current; an output to connect to the at least two LED segments (22, 24); and a current distributing circuit which provides the input current to a single one of the two LED segments when the current is at a peak portion, wherein the current distributing circuit is adapted, when providing the input current to a single one of the two LED segments during the peak portion, to provide the input current to the single one of the two LED segments alternately, and splits the input current into two non-zero currents for different LED segments when the current is in a trough. When all current is provided to one LED segment, the light conversion efficiency is lower than when two segments are driven with lower current. This means the effect which the current ripple has on the light output is reduced. The driving circuit effectively compensates for the current ripple by adjusting the light conversion efficiency so that a flatter light output characteristic is obtained.

Dependencies are inferred from the claim text.