Design Of High-Speed Data Acquisition System With Multi-Channel Based On USB2.0

Data acquisition system is the necessary means to obtain data, it is an important part in the electronics measurement and control system. For the low frequency signal, it can be measured completely and precisely by the low speed data acquisition system, but for those signal such as single-time narrow-pulse signal, high-speed low repeated rate signal and the signal all in a sudden etc, it can not be finished by the low speed data acquisition system, but the high speed, high accuracy data acquisition system can do.In this article, a wide used high-speed and multi-channel data acquisition system is designed based on the current technology of data acquisition. We used intelligent design methods in the circuit design of signal pre-disposal. Namely, it is totally intelligent to choose the signal channel, to adapt the amplify times and the end frequency of the low-pass filter. It becomes more conveniently to operate this system in doing so. Because of the usage of AD7671, the input band-width is much larger and the sampling frequency is much higher. And we use ISP technology to dispose the control of the whole system in order to sample the high frequency signal only because the common microprocessor can't complete real time control. Because of using ISP chip in the system in stead of common TTL part, the whole function of the system and the expansion capability raised consumedly, while the design become much easier and the equipment physical volume become smaller. Meantime, the transmission speed and throughput from data acquisition system to PC is guaranteed by using USB2.0 high speed interface technology.This system has a higher function price ratio with high practical value. It can be used as a general data acquisition apparatus. Also, it can be used as all kinds of static or dynamic states signal analysis instruments by using certain software.