Design And Implementation Of Multi-channel Analog/Digital Data Acquisition Device Based On FPGA

The main function of The Device of Mixed Acquisition of Multi-channel Analog/Digital Data is to complete the multi-channel analog and digital signals acquisition andencoding, In this thesis, an analog and digital multi-channel acquisition circuit based onFPGA is designed for the demand of an aerospace testing tasks.This thesis first elaborates the hardware design of the system, analyzes and compares theother two common designs, details the system of hardware and software design principles ofeach module. In order to improve the accuracy of collected sampling circuit and systemstability, The thesis analyses and optimizes the hardware and software: In the hardware, thesystem uses FPGA as the control core, to control the Analog switches and AD convertercircuit gating and switching, achieve the functions such as the sampling and coding of theanalog signal, the decoding of the digital data, the mixed framing and so on; analyzes theproblem of larger op amp output ripple in the Analog signal conditioning circuitry, whicheffects the sampling accuracy, And one proposed solution is to increase the capacity of the opamp driving a capacitive load,which can improve the system stability. In the software, thethesis describes the ideas of internal FPGA logic design, introduces the multi-synchronousFPGA internal clock domains, achieves the multi-channel sampling timing control based onthe ROM of lookup table structure, and introduces the techniques of mixed framing and thereliability design of the transmission of digital in detail.Finally, the thesis tests the optimization of acquisition circuit, combines with ground testsystem for the editing device functional testing and validation, analyses and processes thecollected data, and redraws the analog signal graphics, the test results prove the device hasreached the mission requirements of the performance indicators.