Design Of Photoelectric Conversion And Data Acquisition System Based On USB2.0

During the science and technologies development in today's world, to make the detection and acquisition more precise in the application of high frequency photoelectric signal detection and storage, there are higher and higher demands for the performance of photoelectric detection and data acquisition system. Traditional photoelectric detection devices can not satisfy today`s scientific research and production because of its low response rate, low transmission rate and inconvenience to install. The emergence of high-speed PIN photoelectric diode and USB2.0 technology can solve the problems above. This thesis describes a photoelectric signal detection and data acquisition system based on USB2.0.In order to accomplish the goal of indoor white light communication signal`s detection and data acquisition (low-frequency range 0-10MHz, high-frequency range 100MHz-1GHz). This thesis makes an overall design for the system to meet the performance index. After the comparison of different core devices, we make a selection of photoelectric conversion device (S5903), A/D conversion chip (MAX115) and USB2.0 interface chip (CY7C68013).In practical software design and hardware design, this thesis realized the hardware design and simulation of high-speed photoelectric conversion and signals processing modules, and then analyzed the parameters of operational amplifier such as circuit noise characteristics and voltage conversion rate; completed the hardware design and circuit board production of USB2.0 high speed data acquisition module, at last finished the data acquisition module firmware programming and debugging by Keil C51 and GPIF Designer software. Combining the DDK software developer's kit and Microsoft Visual C++ 6.0 programming system, this thesis completed the drivers and user application programming work.To evaluate the performance of this system whether meets the index requirements, we do some practical measure and test. The result indicates that the system can accomplish the detection of 10MHz - 1.5GHz white light communication signal, USB2.0 data acquisition module can be input 1-4 channels target signal range - 5V to + 5V. The 12-bits high-speed A/D conversion chip MAX115 has the highest sample rate of 400KSPS. In Experiment the transmission rate can reach 1MB/s - 20 MB/s. This system can realize real time photoelectric conversion and data acquisition of high frequency instantaneous photoelectric signals, and it works steadily and reliably. So this thesis achieves the goal of developing a high-speed photoelectric signal conversion and data acquisition system, which has new characters of high corresponding frequency, high transmission speed and high system integration.