Abstract
Advantage of CMOS image sensor such as high integration and low power makes this kind of image sensor have its position. But tradeoff between dynamic range and output swing is undesirable. In this thesis, a nonlinear A/D converter design for CMOS image sensor is described and designed with a 0.35 um 1P4M process. The nonlinear transfer function of the proposed A/D converter changes the resolution distribution of the output data, thereby improving the overall sensor’s resolution in low illumination and overcoming the effect of the sharp break point in the pixel cell’s photo-electrical characteristic.The A/D converter uses successive-approximation register architecture with current-mode D/A converter. It has input range of 0V to 1.5V and 8-bit output data. The total power consumption is 17.12mW and the total area is about 240000 um2.