High Speed Data Acquisition System Based On FPGA

High speed data acquisition system is the key part of the geological radar, digital oscilloscope and other testing equipment. According to the requirement of geological radar, a high speed data acquisition system based on FPGA is proposed, and the design, assembly and testing of the system are completed.The data acquisition system directly uses the high speed ADC, and the high speed equivalent sampling is achieved by the delay control of the sampling clock. Compared with the traditional method, the design of the circuit is simplified, the process requirement of the circuit is reduced, and the system is more stable and the performance is more excellent.First of all, this paper puts forward the technical index, the overall design scheme and the technical means of the system design process. The overall design of the system is divided into three key modules:control module, A/D conversion module and clock module.Among them, the control module uses FPGA to achieve. Inside the FPGA constructed Nios II core, FIFO buffer, A/D timing control module and clock delay control module. The control of the whole data acquisition system is realized.Secondly, the A/D conversion module uses high speed AD converter ADC16V130 to achieve. Analog input ADC16V130 chip for 2.4Vpp,-3dB bandwidth to 1.4GHz, the highest real-time sampling 130Msps and tracking using the chip built in high performance to maintain and AD conversion circuit, through the sampling clock control, to achieve a good performance of the equivalent sampling rate.In order to ensure the performance of the system, the high precision and low noise clock chip LMK04096 is used to design a high precision clock.Finally, according to the design scheme, the design of the whole system is completed, and the feasibility of the design scheme is verified through the test of the system.After testing, analog input bandwidth of the data acquisition system about for 850mhz, basically reached 1GMHz technical indicators, input gain is12.9db, can satisfy the input range of the ADC, the equivalent sampling rate can reach 8Gsps, basic meet the technical requirements of geological radar.