摘要
用CMOS(complementary metal oxide semiconductor)图像传感器取代传统医用X射线透视仪器对于医疗设备的便携化、数字化具有重大意义。由于医疗应用的特殊要求,对于CMOS图像传感器要求具有12位以上分辨率的输出,因此本文设计了一个具有14位分辨率的流水线ADC(analog digital converter)来满足X射线CMOS图像传感器系统的要求。由于X射线CMOS图像传感器的面积很大,因此将像素阵列分割成若干块同时并行读出。每一块将用到一个14位的流水线ADC。这种并行结构将大大降低对于ADC速度的要求。根据系统要求,本文设计的ADC的速度为3 MS/s.通过采用类似并行流水线ADC的结构,将ADC设计的速度要求降低一倍,缓解由于高精度设计带来的设计压力。仿真结果表明本设计可以达到14位的设计精度。
Objective Using CMOS（complementary metal oxide semiconductor） image sensor to replace traditional X-ray apparatus is a great significance for miniaturization and digitalization of medical equipments.For the special requirements of medical application,the CMOS image sensor output resolution should be more than 12 bits,and in this study we use a 14-bit pipeline ADC（analog digital converter） to meet the system requirements.As the area of X-ray CMOS image sensor is very large,we divide the CMOS image sensor into many partitions,and read data in parallel.Each partition adopts a 14-bit pipeline ADC to readout.The parallel structure greatly reduces the requirement for speed.According to the system requirements,a speed of 3 MS/s is adopted in this work.A pseudo-parallel pipeline ADC has been introduced into this work,which allows to reduce the speed requirement by a half,releasing the design pressure from high precision requirement.The simulation results demonstrate that the design can achieve a 14-bit resolution.
出处
《中国体视学与图像分析》
2011年第1期108-112,共5页
Chinese Journal of Stereology and Image Analysis
