LED driver design for indoor lighting and low-rate data transmission purpose

Abstract

The LED driver design for lighting at the indoor environment, as well as data transmitter with a one-way link (for download purpose), is discussed clearly in this paper. The LED driver performances are already tested with three scenarios approach and it can work properly. Those approaches are 1) single carrier signal generated by signal generator with offset null as an input signal, 2) integrated with the digital block, i.e. Digital-to-Analog converter (DAC) board which has DC component as an input signal, and 3) using the audio signal as input. The contribution in this paper i.e. 1) the LED driver was simply designed and it could be used for signal with multilevel amplitude format, e.g. audio signals, video signals, orthogonal frequency division multiplexing (OFDM) signal format, etc.; 2) low-cost platform which is built from inexpensive general DIP OP-AMP, 3) can dial up 50 kHz of bandwidth; 4) no flicker effect, therefore harmless for human eyes; 5) light weight implementation and 6) simple to operate with manual tuning. Our proposed LED driver is divided into three stages where each of them, have the main functions, i.e. a) DC-offset remover circuit to remove signal input with has DC signal characteristic, DC-offset summer circuit with a variable amplifier as signal conditioning, and voltage follower transistor.