Design And Research Of FPGA Based Signal Acquisition Circuit For A-Si X-ray Flat Panel Detection Array

After decades of development,the economy of China has been greatly improved.At the same time,with the arrival of population aging,China's investment in the health-care industry increased rapidly,the common people pay more attention to personal health.In the medical industry,medical imaging plays an irreplaceable role for the rapid diagnosis and treatment of diseases.At present,with the advancement of medical digitalization,digital medical imaging is widely promoted.The purpose of this paper is to design the corresponding signal acquisition circuit using the existing a-Si PIN structure X-ray flat detector in the laboratory.The analog signal sensed by the detector array is read out and converted into digital signal for subsequent processing.The main work of the thesis includes: designing the signal acquisition circuit by TI 's commercial chip,and then implementing the hardware part by chip selection,circuit design and PCB production.The control code is written by Verilog HDL hardware description language,simulated by Modelsim software,and finally we used Quartus II Software for synthesis,placement and routing,the control code was implemented by Altera Cyclone IV FPGA to control the operation of signal acquisition circuit.In addition,due to the involvement of radioactive experiment,we specifically designed the radiation protection test box for the isolation of Xray.The final experiment and test verifies the functionality of the circuit and successfully acquires analog and digital signals of X-ray.The acquisition time of signal acquisition circuit is about 108.15?s,the maximum operating frequency is 50 MHz,16Bit conversion accuracy and 85 dB dynamic range.Based on the simulation and test results,the acquisition system running stably with a good performance.In summary,signal acquisition circuit we designed meets our requirement.