照明控制应用的LED驱动器

　　照明控制应用的LED驱动器

　　ROHM提供许多外部和集成输出LED驱动器应用范围广。

　　由于种种原因，发光二极管的使用正在增加。与白炽灯相比，LED更高效、体积更小、寿命更长，可以为改进美学提供更大的设计自由度。此外，LED照明的颜色更自然，使其成为照明的首选。易于控制的LED也使它们成为基于传感器输入的智能照明系统的自然选择。控制的一个重要方面是集成电路驱动程序提供的电源管理。

　　LED驱动能力

　　LED需要恒定电流才能产生一致的照明。因此，这就构成了LED驱动器的基本操作要求。电流源的准确性决定了它的客户吸引力。电流波动可能随着电压供应的变化而发生，必须避免。线性稳压器提供一个简单的控制，不需要电磁干扰（EMI）滤波器。然而，它们的功耗可能会变得更高功率应用。降压DC-DC转换器通常作为下一步从一个线性稳压器。

　　When the driver must control several LEDs in series， a boost converter topology is used. In some cases， a buck-boost topology provides the capability to address a variety of application requirements， including the ability to handle voltage extremes.

　　LED drivers can be designed to offer a combination of series and parallel LED control. Devices with this capability built-in provide circuit designers the flexibility to control LEDs in different applications with a single driver， rather than requiring different devices that increase qualification testing. Dimming the light level is a common requirement for lighting. However， there are applications for brighter than normal requirements from the same LEDs. In some cases， lighting design may be able to address both situations with the same LEDs with the right LED driver.