时间数字转换器的设计与应用研究

发布时间：2018-09-18 08:40

【摘要】：三维成像技术是在二维成像技术的基础上引入了景深的数据,为用户提供了更加逼真的视觉体验,受到用户的好评。三维图像传感器具有广泛的市场前景,这从3D电影的风靡便可见一斑。作为相对前沿的一种三维成像方法,直接飞行时间法具有一些独特的优势,例如:测量精度高、速度快、系统体积小和系统鲁棒性高,具有非常重要的研究意义。光子以光速在空间中传播,直接飞行时间法就是准确获得从发射光脉冲到传感器接收到回波的时间,再将时间和距离进行代换,从而得到景深的数据。因此,设计出一种高精度时间间隔测量电路是实现直接飞行时间法三维成像的关键。本文从三维成像的应用背景出发,对高精度时间间隔测量电路——时间数字传感器进行了深入的研究,分析了各种时间数字传感器的基础结构,对比它们在各项性能指标方面的表现,选定了两步式时间数字传感器作为重点研究对象。本文基于GSMC 0.18μm CMOS工艺设计了一种基于脉冲计数器与延迟线结构的两步式时间数字转换器,位数为10 bit,在285 MHz的参考时钟频率下工作,达到了219 ps的时间分辨精度与112 ns的动态范围,在线性度的表现上,其微分非线性误差与积分非线性误差分别为±0.52 LSB与±0.80 LSB,时间测量的失调误差不超过3.5%。与此同时,本文基于所设计的两步式时间数字传感器设计了用于三维成像的像素读出电路。采用雪崩光电二极管作为光子探测器件,除了最主要的模块——时间数字转换器之外,像素读出电路还包括前端电路、接口电路等电路子单元。本文所设计的像素面积为110μm2,帧速率1.5 MHz。最后,对像素进行了阵列化设计与版图设计,阵列规格为16×16,阵列面积为2000μm×2300μm。
[Abstract]:Three-dimensional imaging technology is based on two-dimensional imaging technology, the introduction of depth of field data for users to provide a more realistic visual experience, users praise. 3D image sensor has a wide market prospect, which can be seen from the popularity of 3D movies. As a relatively advanced 3D imaging method, direct flight time method has some unique advantages, such as high measurement accuracy, high speed, small system volume and high system robustness. Photons propagate at the speed of light in space. Direct time of flight (TOF) method is to accurately obtain the time from emitting light pulse to receiving echo from the sensor, and then replace the time and distance to obtain the data of depth of field. Therefore, the design of a high precision time interval measurement circuit is the key to realize the direct time of flight method 3D imaging. In this paper, based on the application background of 3D imaging, the time digital sensor, which is a high precision time interval measuring circuit, is studied deeply, and the basic structure of various time digital sensors is analyzed. Compared with their performance, two-step time digital sensor is selected as the key research object. In this paper, a two-step time-digital converter based on pulse counter and delay line structure is designed based on GSMC 0.18 渭 m CMOS process. The bit-number of 10 bit, works at the reference clock frequency of 285 MHz. The time resolution accuracy of 219 ps and the dynamic range of 112 ns are achieved. The differential nonlinear error and integral nonlinear error are 卤0.52 LSB and 卤0.80 LSB, respectively. At the same time, a pixel readout circuit for 3D imaging is designed based on the designed two-step time digital sensor. The avalanche photodiode is used as the photon detector. In addition to the most important module, the time digital converter, the pixel readout circuit also includes the front-end circuit, the interface circuit and other circuit sub-units. The pixel area is 110 渭 m ~ 2 and the frame rate is 1.5 MHz.. Finally, the array design and layout design are carried out. The array size is 16 脳 16, and the array area is 2000 渭 m 脳 2300 渭 m.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TH714

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