Design And Implementation Of The 4Gsps High-speed Data Acquisition System’s Front-end Module

Nowadays, the data quantity and the data rate of communication system are increasing rapidly, so the realization of high speed data acquisition system has turn into a hot project for research. This paper gives an account of the design and realization of the 4Gsps high-speed data acquisition system’s front-end module.Based on the FMC interface, this paper designs and realizes a high-speed sampling card which has four channels and its sample rate can go up to 5Gsps. We select EV10AQ190, provided by E2V Company, as high-speed sampling card’s ADC chip. For the purpose of satisfying deferent needs, multiple sampling clock modes are designed for high-speed sampling card, including the internal sampling clock mode, external reference clock mode and external sampling clock mode. So as to protect the high-speed sampling card, we choose to use the temperature sensor chip ADT7411 to observe the temperature of the sampling card. The control interface of the sampling card uses the I2C. And the board card (ML605) realizes the configuration of the high-speed sampling card through this I2C bus. The entire system takes two sampling card to realize the data acquisition system which has eight channels. After testing, the performance of the system can achieve the demand of the project.At the same time, because the project has demand of the input signal’s voltage range, this paper also completes an eight channel signal conditioning circuit to satisfy the project’s demand. Each channel includes a piece of digital attenuator(HMC542), a piece of programmable amplifier (DVGA2-33+) and a piece of fixed amplifier (ERA-2+), the signal conditioning circuit’s maximum attenuation factor can be up to-28 dB and its maximum amplification factor can be up to 35 dB. DSP completes the configuration of the signal conditioning board through the SPI bus.