High efficiency multi-channel LED driver based on SIMO switch-mode converter

This paper presents a new method to drive multiple LED strings efficiently. The proposed driver is based on single-inductor multiple-output (SIMO) switch-mode converters. Because the proposed driver gets rid of linear current regulators and maintains desired constant current of each string directly, it maximizes the overall efficiency and handles mismatching problems of the conventional driver. The simulation results show excellent performance on four-string LED with four 1W LEDs in each string including individual dimming. The measured efficiency was improved at least by 15% compared with the conventional driver of linear current regulators.