← 返回 JSSC 论文列表JSSC 2008第4期Image Sensors0.18-μm 2P3MCMOS Image Sensor
A 200- /22V/e CMOS Image Sensor With 100-ke Full
开发了一种高灵敏度CMOS图像传感器，通过新型像素设计实现高满阱容量。
200- V/e转换增益, 100-ke满阱容量, 2.2-e rms噪声底限
CMOS图像传感器高灵敏度满阱容量浮动扩散电容自对准偏移结构
▸采用小浮动扩散电容连接横向溢出集成电容
▸自对准偏移结构抑制转换增益变化
▸双信号输出确保高灵敏度和高满阱容量
Abstract
A high-sensitivity CMOS image sensor keeping a high full-well capacity has been developed by introducing a new pixel having a small floating diffusion (FD) capacitance connected to a lateral overflow integration capacitor (LOFIC) through a MOS switch. The conceptual advantage of the small FD approach over conventional column amplifier approaches is compared and demonstrated. To ensure both the high sensitivity and the high full-well capacity, the low-light and the bright-light signals (S1 and S2) are output and reproduced without a visible SNR degra- dation at the S1/S2 switching point. As the most critical problem, the increase of the conversion gain variation in this approach is suppressed by applying a self-aligned offset structure to the small FD. A 1/4-in VGA format CMOS image sensor fabricated through 0.18- m 2P3M process achieves 2.2-e rms noise floor with 200- V/e conversion gain and 100-ke full-well capacity.