Research On Ultra-short Shutter Time X-ray CMOS Image Sensor

The study of high-energy-density physics under extreme conditions is likely to lead to scientific breakthroughs and technological innovations.It is a research field that countries are competing to develop.In high-energy-density physics experiments,appropriate precision diagnostic techniques must be available to observe and control the experiments well and provide the necessary means for physical model analysis.The light excited by the laser inertial confinement fusion(ICF)experiment in high-energy-density physics is in the X-ray frequency band,so the research on the ultrafast phenomenon of X-ray precision diagnosis technology has very important scientific significance and application value.This thesis focuses on the key component of the X-ray ultra-fast phenomenon precision diagnosis technology-ultra-short shutter time CMOS image sensor.The thesis first analyzes the interaction between X-rays and matter and the principle of PN junction detection.Then the pixel cell circuit with Current-steering structure is designed,and the response curve under different photo-generated currents obtained by simulating the unit pixel circuit shows that the pixel cell circuit can work for 120 ps exposure time.The structure of the H clock tree is used for signal transmission,so that the shutter control signal is evenly distributed in the entire array,and a buffer with a fast falling edge is designed to be placed in the clock tree path to maintain the falling speed of the shutter control signal.The voltage-controlled delay circuit is used to generate the exposure end signal from the exposure start signal,and the exposure time can be adjusted in a wide range by the control voltage;in the 8×8 sub-unit,the unbalanced inverter is used in a hierarchical parallel connection mode to enhance the driving ability of the control signal.In consideration of not adding extra pixel array area and matching,the inverter resources are distributed in each pixel unit with a center-symmetric design.Finally,row selection and column selection are completed through the shift register,and the pixels in the array are read out sequentially.The simulation clock frequency is set to 10 MHz,the exposure time is set to 180 ps,and the 8×8 array and 64×1 array are pre-simulated to verify the function of the CMOS image sensor circuit.The total equivalent output noise is 0.238 m V.The output swing amplitude is 1.51 V.The dynamic range is 76.04 d B,and the power consumption is14.05 m W.