Design Of High-speed Remote Transmission System Based On LVDS

The full name of LVDS is Low-Voltage Differential Signaling. It is a kind of signaltransmission mode proposed by National Semiconductor Corporation in the end of the 20thcentury, and also is a level standard. LVDS interface technology can be used as a solution ofdata transmission with high performance, which supports the data transmission within asystem (such as PCB) or among systems (such as crates). Compared to the RS485 and IEEE1394 and many current interface and protocol standards, LVDS offers high-speed, highanti-noise, low EMI emissions, low-power, also with low cost and simple in design. Theapplication background of the paper is aerospace experiment, which require long distance,high-speed and real-time mass data transmission between solid-state memory and test bench.In the paper, a high-speed remote transmission system based on LVDS is designed. Thesystem composition and control process are discussed, and key technologies in the applicationare analyzed. Finally, the 480Mbit/s data rate has been realized between the two systemswithin 50 meters. The full text can be summarized as follows:1) According to the background of the thesis and application requirements, some currentinterface standards are discussed. And the advantages of LVDS serial transmission areintroduced. By comparing the different structure and topological that LVDS devices use,finally the LVDS devices with point-to-point bus and embedded clock SerDes are used inthe design. The cable driver and cable equalizer are used for realizing the long distancetransmission.2) Key technologies are analyzed for the high-speed differential signaling circuit design,including signal integrity analysis and data processing in the transmission. In order toavoid or reduce the signal reflection and cross-talk, mainly method is the impedancematching. And the PCB layout should based on both high-speed circuits and differentialsignal. To ensure the continuity of data transmission, a solution that use the FIFO bufferand alternately send true and false data is made. 3) The system is designed with modular technology. The LVDS receiving circuit andtransmitting circuit are designed. And the data transfer scheme between memory and testbench are given. FPGA is used for controlling data communication in the system, andlogic function modules are designed with VHDL. High-speed data transmission betweensolid-state memory and test bench was realized at last.