Design Of Sigma Delta ADC In Seismic Apparatus

Seismic apparatus is the most fundamental equipment and also the most critical in the seismic exploration. Analog-digital convertor is the most important and key part of the seismic apparatus, because its performance directly affect the accuracy of the data it collected, and the accuracy of oil storage location.The thesis studyed the Sigma Delta mosulator and the decimation filter deeply, the main content is listed as following:1.Discussed the principle of Sigma Delta ADC, and analyse the technology of the Sigma Delta ADC:over-sample technology, noise shaping, filter and decimation.2.Studyed the the component parts, the operating principle and the characters of the Sigma Delta modulator, and determine the structure and the circuit parameters of.the modulator, according to the targets of the task, and then do the simulation in TINA Pro.3.Discussed the principle of the decimation filter and adopt multi-stage structure to reduce the calculated amount and the hardware resource. Finished the design of each filter using MATLAB.4.Finished the hardware realizition of FPGA in QuartusII using Verilog HDL. Using Hogenauer annihilate theory, limit word length. IP core, CSD coding, poly-phase structure and so on to reduce the hardware resource it occupied.5.Finally, testing result of key units was given in laboratory.