Design Of Weak Signal High-Speed Data Acquisition System Based On FPGA

Data acquisition system is the system that collect target signal, process and store it,form the data format computer can handle, and finally output it with various forms. Nowmost of the data acquisition systems are for strong signal, there are few for weak signal.However, no matter in scientific research or in daily engineering practice, the need to captureweak signal is common. Therefore, it is necessary to do research on the acquisition systemwhich collection object is weak signal covered by the background noise. It is widely used inthe physics, biology, mechanics, power and other fields. In addition, high-speed, real-timeprocessing, noise suppression, improving SNR are the goal of weak signal data acquisition.According to the above requirements, this thesis designs the weak signal data acquisitionsystem with FPGA as the core chip.This thesis describes the key technologies of the system, including digital multi-pointaveraging technology, A/D conversion technology, logic control and signal processingtechnology, data transmission technology, etc. With these key technologies as the theorybasis, the author puts forward the system overall design scheme, and simulates linearaccumulative average algorithm in Matlab, analyzes and discusses its performance. In thesystem hardware design, the author designs front-end acquisition circuit, memory circuit,FPGA control and configuration circuit, USB interface circuit, clock circuit, power circuitrespectively, draws six-layer PCB with principle of high-speed circuit PCB design. In thesystem logic design, it can be divided into7modules based on module design idea. There areA/D controller, accumulative average device, data control module, DDR SDRAM controller,USB interface controller, FIFO buffer module, PLL module. Use Verilog HDL to achievetheir function, and verify their functional correctness with Mentor’s ModelSim software.The system realizes the goal of high-speed transmission, real-time processing, noisesuppression and improving the SNR. It meets the design requirements.