用于视觉假体的新型高动态范围图像传感器像素单元电路设计

摘要

A novel pixel circuit of high dynamic range CMOS image sensor (CIS) was presented for the applications of visual prosthesis, which used the conditional overflow capacitors and multiple integration technologies to achieve high dynamic range, high sensitivity and high signal to noise ratio (SNR) requirements. The designed circuit was simulated using Chartered Semiconductor 0.35μm CMOS process model parameters, the simulating results showed that the dynamic range was increased by about 62dB than the traditional 4 Transistor Active Pixel Sensor (4T APS) circuit, and the SNR and sensitivity were as high as the 4T APS in weak signal conditions.%针对于视觉假体的应用领域,本文提出了一种新型的高动态范围的CMOS图像传感器(CMOS Image Sensor,CIS)像素单元电路,该电路采用了列共用单元的条件溢出电容和多次积分技术,大大提高了图像传感器的动态范围,同时使其在低光照时保持较高的灵敏度和信噪比,采用了特许半导体公司的0.35μm CMOS工艺参数对该电路进行了仿真,结果表明所设计的电路比普通四晶体管有源像素传感器(4 Transistor Active Pixel Sensor,4T APS)电路的动态范围提高了约62dB,并且在低光照时保持了普通4T APS的高信噪比和灵敏度的特点.