Modular design of channel number adjustable and high precision acquisition system based on FPGA

In the development of acoustic camera, aiming at the need of high-precision acquisition of acoustic field signals and real-time transmission of multi-sensor information, a modularized data acquisition system is designed, which integrates PGA, Σ-Δ ADC, FPGA as well as Gigabit Ethernet communication, and the condition of channel extension is given. According to the performance test, it shows that the sampling error of this module is 0.000 2%, the self-noise is 9 μV, and it has the advantages of 110 dB dynamic range under the bandwidth of 55 kHz, not only its performance better than the most often used multi-channel data acquisition device of vibration acoustics, but also has the characteristics of good extendibility and lower development cost.