基于FPGA的地震数据采集单元改进与实现

Improvement and Implementation of FPGA Based Seismic Data Acquisition Unit

针对国内普遍使用的CirrusLogic地震数据采集套片的不足,开发了一种采用ADS1282的新型四通道24位地震数据采集单元,在采样率1000SPS,前放增益0dB时等效输入噪音小于1.31μV,谐波失真小于0.00013%,满足国家标准规定的石油地震数据采集系统A级指标要求,具有性能更优、功耗更小、成本更低的优势;采用FPGA作为控制器,攻克了协调控制多路ADS1282和FPGA产生测试位流等关键技术;配套开发了基于LabVIEW的采集单元测试系统,采用USB通信并供电,整套系统也可作为便携式检波器测试仪使用。

A 4 channel 24--bit high performance seismic data acquisition unit is designed and implemented with ADS1282 and FPGA, aiming for instead of the common used Cirrus Logic seismic prospecting chips CS3301A, CS5372A and CS5376A. It has higher performance with the Equivalent Input Noise lower than 1.6 μV and the Total Harmonic Distortion lower than 0. 00013% （under 1000SPS and 0dB preamplification）, which achieves grade A channel module according to the petroleum seismic data acquisition system national standard. （）tber wise, it has lower power consumption and lower cost. In this unit FPGA is used as controller to solve the two key problems of multi-channel control and Test Bit Stream generating. Moreover, a 1.abVIEW--based position machine program is developed to test the unit as well as independently perform as a portable geophone tester.