适用于照明和可见光通信的宽输入电压范围的分段式LED驱动电路

摘要

When illumination is combined with visible light communication (VLC), the light emitting diodes (LEDs) and their drivers gain a broader application chance than before. The LED drivers for illumination and VLC need to meet both lighting electrical standards and communication requirements. Based on an input-voltage-adaptive constant-power illumination scheme, a partial return-to-zero on-off-keying (RZ-OOK) modulation scheme is proposed for a multi-segmented LED driver to have dual functions of illumination and VLC within a wide input voltage range. A prototype LED driver was implemented for experiments. Some test results show that under the illumination mode, both power factor (PF) and total harmonic distortion (THD) values satisfy the electrical standards for lighting, and the output power could keep constant. Under the continuous few-frame VLC mode, the PF and THD values still satisfy the electrical standards for lighting, and the output power regulation is tight. Under the continuous multi-frame VLC mode, although the PF values could satisfy the electrical standards for lighting, the output power regulation is poor. Therefore, the prototype under the continuous few-frame VLC mode is suitable for both illumination and VLC applications, while the prototype under the continuous multi-frame VLC mode is more suitable for VLC applications.%当照明与可见光通信(VLC)相结合时,LED及其驱动电路便获得了更宽广的应用舞台.适用于照明和可见光通信的LED驱动电路既需要满足电气照明标准又需要满足通信要求.本文以输入电压自适应的恒定功率照明为主体,提出局部归零开关键控(RZ-OOK)调制的LED电流控制方法,使分段式LED驱动电路在宽输入电压范围内兼具照明和可见光通信的功能.样机的实验测试结果表明:照明模式下,PF值和THD值都符合电气照明标准,而且输出功率可保持恒定;连续少帧VLC模式下,PF值和THD值也都符合电气照明标准,而且输出功率波动较小,适合照明和可见光通信两用;连续多帧VLC模式下,仅PF值符合电气照明标准,而且输出功率波动较大,更适合可见光通信的应用.