Monte-Carlo Simulation of Current Derating Characteristics of LED Parallel Circuit

ZHENG Tong-chang^{1}, LI Bing-qian^{2}, XIA Zheng-hao^{1,2}

1. Institute of Optoelectronic Material and Technology, South China Normal University, Guangzhou 510631, China;
2. Deptartment of Physics, Foshan University, Foshan 528000, China

Based on Monte-Carlo simulation, the current derating characteristics with LED parallel circuit is studied, especially the probability distribution of current derating of a series (2 ≤n≤15) of LED parallel circuit, given the forward voltage drop values of LED after bin agree with Gaussian distribution. The simulation shows that the probability distribution of current derating deviates Gaussian distribution, namely the left and right of the peak point of probability density function is asymmetric, Of which the left side is more sharp than the right side. The probability distribution of current derating is more and more tend to be Gaussian distribution as the quantity of parallel LED increasing. As the probability of occurrence that the current bearing by LED exceeds its rated current increasing, the current derating needed by the parallel circuit increases gradua-lly but the increase rate tends to be reduced. The current derating is about between 20% and 30% when the probability is between 0.01% and 1%. The current derating needed by the parallel circuit increases gradually but the increase rate tends to be reduced as the quantity of LED increasing (n>6). The simulation results can be applied to the LED interconnection array.

ZHENG Tong-Chang,LI Bing-Gan,JIA Zheng-Gao. Monte-Carlo Simulation of Current Derating Characteristics of LED Parallel Circuit[J]. CJL, 2010, 31(4): 590-594.