基于SPWM的二次优化与实现

Optimization and Implementation of SPWM Algorithm

小点距LED显示屏要显示出具有高对比度、更加细腻的图像,需要能够输出高等级灰阶的驱动芯片。SPWM (分散式脉宽调制技术)算法通常用于处理高灰阶图像,但是此算法在低灰度表现和图像均匀性上有一定缺陷。针对低灰效果不佳和多行扫下刷新率不足的问题,在SPWM算法的基础上提出低灰数据的分配优化和子周期的二次优化,同时用硬件语言实现优化后的SPWM算法并进行仿真验证。在低灰情况下,输出波形的均匀度提高明显,整体刷新率能够提高2倍以上。

LED driver chips can output high level of grayscale and they are widely used in fine pitch LED to display more exquisite and contrastive images.The SPWM algorithm is usually used to deal with high grayscale images,but there are some defects when the grayscale is low and the evenness of the image is poor.This paper proposes"optimization of distributing the low gray data"and"optimization of subcycle"to solve the problems of poor performance in low gray data and insufficient refresh rate in the situation of multi-row sweep,they are based on SPWM algorithm.The optimized algorithm is implemented with hardware description language and it has been simulated and verified.The evenness of output waveform increases a lot in the situation of low grayscale,and the refresh rate may increase more than 2 times.