EMCCD Imaging Component Research

Over the last ten years,with the quick development of Electron Multiplying CCD(EMCCD),it has become one of the core of low light imaging,and is widely used in military,astronomy and other fields.The quantum efficiency of EMCCD is high,and the detection ability of the low light image is strong.EMCCD is an all-solid-state electron multiplying device,which has low manufacturing cost,long life and high stability.The adjustable gain multiplying characteristics allow it to meet all-day,large dynamic range of application requirements.This paper designs EMCCD drive circuit with EL7457 as the core,multiplying clock drive circuit with DAC chip as the core,digital control circuit with FPGA as the core,EMCCD output signal processing circuit with AD sample chip as the core,and image acquisition output circuit with Camera Link communication interface as the core based on the working principle,device characteristics and requirements for driving signals of EMCCD.Firstly,the paper analyzes the advantages and disadvantages of different voltage transfer circuit,and finally chooses to use EL7457 to design EMCCD drive circuit.EL7457 has four output channels,the operating voltage meets the requirements and it has peak output current of 2A and high capacitive drive capability.The multiplying gate is driven by sine wave to reduce power consumption.The FPGA is used to Compile time sequence of the EMCCD drive signal,control AD sample chip and Compile time sequence of Camera Link interface.The FPGA works in parallel,the working frequency is very high,has high time precision and the phase relationship between each output signal can be finely controlled.The selected AD sampling chip in the output signal processing circuit can control the sampling time of correlated double sampling in real time,and the debugging is simple.The timing of Camera Link is very simple.The Camera Link interface has high transmission rate,suitable for real-time transmission of the camera signal,and the host computer can save the raw data,which is convenient for data analysis later.After completing the circuit design,combined with the debugging experience of digital analog mixed circuit,the debugging of the circuit is completed,which makes the signal in the system meet the design requirements.After the system test,the image acquisition card is used to collect the image,and the system can achieve 25 frames per second of real-time imaging and has high signal to noise ratio.