High-Efficiency Multiple-String Linear LED Driver with Genetic Algorithm for Low Power Application

This paper presents a high-efficiency multiple-string linear LED driver with genetic algorithm (GA) based configuration. Compared with traditional LED drivers, linear LED drivers have advantages of high efficiency, simple structure, low cost and long life-time. To achieve the high efficiency target for multiple-string linear LED driver, the configuration of LED number in each string is a great challenge. In this paper, a method based on genetic algorithm is proposed for the string LED number (i.e. string voltage) optimization. The system efficiency analysis with input voltage and LED current is introduced. And, the GA design flowchart and interface are provided. With the developed GA algorithm code, the optimal voltage for each string can be calculated. To validate the methodology, simulations are carried out to compare the GA based configuration and other four references. The results show that the GA based configuration can achieve the highest efficiency of 96%, which is >8% higher than the other configurations under the same condition.