1. Wide dynamic range linear‐logarithmic CMOS image sensor using photogate and cascode MOSFET
- Author
-
B.-S. Choi, H.H. Lee, Pyungho Choi, M. Bae, J.-K. Shin, and Sungho Jo
- Subjects
010302 applied physics ,Physics ,Pixel ,Dynamic range ,010401 analytical chemistry ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,01 natural sciences ,Active load ,0104 chemical sciences ,0103 physical sciences ,MOSFET ,Wide dynamic range ,Hardware_INTEGRATEDCIRCUITS ,Electronic engineering ,Sensitivity (control systems) ,Cascode ,Electrical and Electronic Engineering ,Image sensor ,ComputingMethodologies_COMPUTERGRAPHICS - Abstract
A wide dynamic range CMOS image sensor is proposed, exhibiting a linear response at a low illumination level and a logarithmic response at a high illumination level. To maintain high sensitivity and to improve the dynamic range of the proposed pixel, a cascode MOSFET is integrated into the structure of the proposed pixel, along with a photogate. The applied photogate voltage reduces the sensitivity of the proposed pixel under the linear response regime, at a moderate illumination level. Under high illumination levels, the biased cascode MOSFET serves as a voltage-light-dependent active load and is responsible for logarithmic operation. The dynamic range of the proposed pixel can be improved by adjusting the sensitivity and the basis of the logarithmic response.
- Published
- 2016