Wide dynamic range linear‐logarithmic CMOS image sensor using photogate and cascode MOSFET. Issue 3 (5th December 2016)

• Record Type: Journal Article
• Authors: Bae, M.; Jo, S.‐H.; Choi, B.‐S.; Lee, H.H.; Choi, P.; Shin, J.‐K.
• Is Part Of: Electronics letters. Volume 52:Issue 3(2016)
• Page Start: 198
• Page End: 200
• Publication Date: 2016-12-05
• Subjects: CMOS image sensors -- MOSFET; wide dynamic range linear‐logarithmic CMOS image sensor -- cascode MOSFET -- photogate MOSFET -- illumination level -- logarithmic response -- linear response regime -- voltage‐light‐dependent active load -- photogate voltage; Electronics -- Periodicals; 621.381
• DOI: 10.1049/el.2015.2907
• Languages: English
• ISSNs: 0013-5194

Abstract

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.