A linear stepping PGA used in CMOS image sensors  

作　　者：徐江涛 李斌桥 赵士彬 李红乐 姚素英 

机构地区：[1]School of Electronics and Information Engineering,Tianjin University

出　　处：《Journal of Semiconductors》2009年第2期57-60,共4页半导体学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (No. 60576025);the Tianjin Innovation Special Funds forScience and Technology, China (No. 05FZZDGX00200).

摘　　要：A low power linear stepping digital programming gain amplifier （PGA） is designed for CMOS image sensors. The PGA consists of three stages with gain range from one to nine, The gain is divided into four regions and each range has 128 linear steps. Power consumption of the PGA is saved by good tradeoff between variation of amplifier feedback coefficient, pipeline stages and gain regions. With thermometer-binary mixed coding and linear pipeline gain stepping, the load capacitance keeps constant when the gain of one stage is changed. The PGA is designed in the SMIC 0.18 μm process. Simulation results show that the power consumption is 3.2 mW with 10 bit resolution and 10 MSPS sampling rate. The PGA has been embedded in a 0.3 megapixel CMOS image sensors and fabricated successfully.A low power linear stepping digital programming gain amplifier （PGA） is designed for CMOS image sensors. The PGA consists of three stages with gain range from one to nine, The gain is divided into four regions and each range has 128 linear steps. Power consumption of the PGA is saved by good tradeoff between variation of amplifier feedback coefficient, pipeline stages and gain regions. With thermometer-binary mixed coding and linear pipeline gain stepping, the load capacitance keeps constant when the gain of one stage is changed. The PGA is designed in the SMIC 0.18 μm process. Simulation results show that the power consumption is 3.2 mW with 10 bit resolution and 10 MSPS sampling rate. The PGA has been embedded in a 0.3 megapixel CMOS image sensors and fabricated successfully.

关 键 词：CMOS image sensor programmable gain amplifier linear stepping low power consumption 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]