【作者】 王艳；

【导师】 李斌桥；

【作者基本信息】 天津大学 ， 微电子与固体电子学， 2012， 硕士

【摘要】 相对于CCD,CMOS图像传感器具有低成本、低功耗、易集成和可高速灵活读取等优点,因此在消费数码、医学成像、工业监控、高清直播、视频通讯等诸多领域,CMOS图像传感器正逐步取代CCD图像传感器的主流地位。本论文主要研究高性能CMOS图像传感器控制电路的设计。CMOS图像传感器控制电路是整个系统中最为重要的一部分,主要包括曝光控制电路、读出控制电路、I2C总线控制电路、APB总线控制电路、暗电流消除电路等模块。本论文实现了CMOS图像传感器的滚筒式曝光控制时序,采用I2C总线和APB总线设计完成芯片寄存器控制界面,利用像素阵列的遮黑行消除暗电流噪声。另外,本论文研究了低功耗技术在CMOS图像传感器设计中的应用,采用门控时钟设计降低系统在待机状态的功耗,并通过电压补偿使得所有像素的复位电平相等,从而完善了传统的CDS电路。为了消除CMOS图像传感器中随机变化的行噪声,本论文在传统相关双采样的基础上,提出了一种新的读出时序。该时序采用行相关双采样方法,同时对相邻的两行像素进行操作,在采集图像信号的同时,把行随机噪声也采样到电容上,进行全差分操作,将行噪声消除。设计完成的CMOS图像传感器芯片基于dongbu 0.18μmCMOS工艺实现。芯片大小为1/6英寸,采用2.8μm像素640×480阵列,暗电流为3mV/s,动态范围为62dB。传感器工作速率为每秒20帧,满足消费类产品的工作要求。测试表明,本论文提出的新时序能够有效消除图像横纹噪声,信噪比从38dB提高到41dB,图像质量明显改善。芯片在待机状态下的电流仅为30uA,相比传统设计方法,功耗降低了60%。更多还原

【Abstract】 Compared with CCD, CMOS Image Sensor has many advantages, for example, low cost, low power consumption, easy integration and flexible high-speed reading, etc. So in the areas of consumer digital, medical imaging, industrial monitoring, high definition broadcast and video communications, CMOS Image Sensors are gradually replacing the mainstream status of CCD Image Sensors. This paper mainly research on the controlling circuit system of high performance CMOS image sensor.The controlling circuit is the most important part of the CMOS Image Sensor system, including exposure control circuits, read-out control circuits, I2C bus control circuit, APB bus control circuit and the darkcurrent cancellation circuit modules.A Rolling Shutter timing control circuit of CMOS Image Sensor is implemented in this paper, using I2C and APB bus as the register control interface.In addition, the low power consump-tion design technology in the design of CMOS Image Sensor is studied, and clock gating is used to reduce the power consumption of standby state. By compensation of voltage, the reset level of all pixels are equal, the traditional CDS circuit is improved.In order to remove temporal row noise in CMOS image sensor, a new readout timing based on conventional correlated double sampling is proposed in this paper. The new readout timing is row correlated double sampling, operating two rows at the same time. Temporal row noise is sampled to the capacitor at the same time when sampling the image signal, and removed by the switch capacitor amplifier.The CMOS image sensor is completed and implemented based on dongbu 0.18μm CMOS technology. The chip size is 1/6 inch, pixel array is 640×480, and the pixel size is 2.8μm, dark current of pixel is 3mV/s, the dynamic range is 62dB. The test results show that the new timing control present in this paper can effectively eliminate the row noise, and the imge quality is significantly improved. The standby current is only 30μA, compared to traditional design methods, the power consumption of the chip is reduced by 60%.更多还原