Study On The CMOS Image Sensor

This paper is mainly a part of research work on a paramount project to tacklein Tianjin Science & Technology Committee "High Performance High DynamicCMOS Image Sensor Design". With the mature of CMOS technology and thedevelopment of solid image sensor, CMOS Image Sensor obtains high speedprogresses. With the advantages of low power dissipation, large dynamic range,high reliability, high integration and cheapness, It has become the key facility ofimage processing technology and has been applied to a great many fields such asvideo camera, digital camera, mobile communication, safeguard, car airbag andfingerprint identification. The accomplishment of this project can settle a strongbase to design other ASICs and implement system integration, and the productswill have a wide market. During my graduate design, I have taken part in the design of the pixel andpart of analog circuits. The article mainly discusses the design of dual integrationdual sampling pixel, column amplifier and the ADC driving amplifier. Firstgeneralize the development of CMOS image sensor and key factors in the design.Divide the system into several modules according to the application, and calculatetheir performance targets. Based on the concept of pixel, analyze the noise of pixel,simulate the circuit by Hspice and give the process of the design of pixel. Studythe important parts of amplifier, such as current source, switched capacitor andcommon-mode feedback, finish the design of the two type of amplifiers withappropriate structures, and do simulation with Hspice. Design the layout of theanalog circuit based on the study of the matching rules. The simulation results byHspice indicate that multiple sampling enhancing dynamic range and theamplifiers can work properly, achieved the performance of the modules.The creative work of this article includes: finished the circuit design of dualintegration two sampling pixel which has large dynamic range. Designed a twostage amplifier with Miller compensation capacitor in narrow space, and designeda high speed Cascode with common-mode feedback circuit.