An AC input inductor-less LED driver for efficient lighting and visible light communication

This paper presents an ac-powered inductor-less light-emitting diode (LED) driver, which can simultaneously provide efficient illumination and data transmission capability by modulating light output. The proposed driver does not have passive components' speed limitation compared to the conventional switching converter-based driving solutions for visible light communication (VLC). Besides this, harmful low-frequency flicker is mitigated with an accurate 1/x circuit and the dimming compensation method. In addition, the digitalized power stage and controller utilized in the proposed driver can achieve smooth transitions among multiple current paths, while the keep-and-restore technique and auxiliary turn-on switch help to further increase the VLC data rate. The integrated circuit of the proposed driver is implemented and fabricated with a 0.35-μm , 120-V high-voltage CMOS process. Measurement results show that under a 110- VAC, 60-Hz input, the peak efficiency of the proposed design is over 89% and the low-frequency flicker is reduced to below 10%. The driver supports up to 8-Mb/s on-off keying non-return-to-zero data transmission for a 1-m distance between the LED module and the receiver. © 1966-2012 IEEE.