一种大功率低噪声的智能可调LED驱动设计方法

Design method for high power and low noise intelligent adjustable constant current source

针对大型LED显示屏驱动中恒流源功率较小、调光不便捷,其开关特性导致的噪声大的问题,提出一种体积小,适用功率大且纹波效果较好的智能优化式恒流LED驱动设计方法。该设计在以往低电流的基础上进行改进,通过运放反馈调节将输出电流的开关特性转换为线性,辅以通断RCD回路(峰值吸收回路)和构建优化式大电流环式PCB布局,能进行光源检测的电流转脉宽式精准调光,输出能够较完善地抑制开关噪声。该设计方法能实现上位机网络远程数字调光,内、外部模拟调光,多路板载级联的智能控制。实验表明:该恒流驱动输出电流可达10A,功率可达370W,输出电流误差小于1%,驱动光源光功率稳定,光照分布均匀,具有较好的纹波效果,稳定可靠。

Aiming at the problem that small constant current source power,inconvenient dimming,and the noise caused by its switching characteristics is large,an intelligent optimized constant current driving design method with small size,high power,and good ripple effect is proposed.The design is improved on the basis of the previous low current,and the switching characteristics of the output current are converted to linear through feedback regulation,supplemented by switching the RCD loop（peak absorption loop）and constructing an optimized high-current loop PCB layout.The light source detects the current-to-pulse-width precision dimming,and the output can perfectly suppress the switching noise.The design method can realize remote digital dimming of the upper computer network,internal and external analog dimming,and intelligent control of multiple on-board cascades.Experiments show that the constant current drive output current can reach 10 A,the power can reach370 W,the output current error is less than 1%,the drive light source has stable optical power,uniform illumination distribution,good ripple effect,stable and reliable.