阵列型图像传感器模数转换技术

摘要

阵列型图像传感器的信号读出方式对整个传感器的性能有较大的影响。在新型的数字化图像传感器中，光电信号的多路传输在数字域实现，实现了信号的无损传输，提高了图像传感器的通道隔离度及抗干扰能力。模拟数字转换器（ADC）是数字化图像传感器的重要组成部分，其性能对整个成像系统的性能有重大影响。以阵列型图像传感器对ADC的要求入手，分析了ADC各性能参数对阵列型图像传感器性能的影响，介绍了数字化图像传感器的各类结构及适用于阵列型图像传感器的不同ADC及其实现方式。CMOS工艺技术的发展使得像素级ADC技术进入实用化阶段，像素级ADC技术可以利用数字积分技术有效提高图像传感器的动态范围，使得光电信号积分及多路传输都在数字域进行，极大地提高了图像传感器的性能。%The photo signal readout plays an important role in array image sensors. The digital image sensor enables photo signal multiplexing and transmission losslessly in digital domain, increasing the channel isolation and making the sensor immune to interference. Analog to digital converter is a major component in digital image sensors and it is critical to the performance of the image sensor. Based on the requirements of the array image sensor to ADCs, the influences of the ADC to the image sensor performance are analyzed. The digital image sensor architectures and different types of ADC implementation are introduced. The development of the CMOS technologies makes the pixel-level ADC applicable, extending the dynamic range of the image sensor and enabling the signal integration in digital domain which improves the image sensor performance greatly.