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A noble Sample-and-Hold Circuit using A Micro-Inductor To Improve The Contrast Resolution of X-ray CMOS Image Sensors  

Lee, Dae-Hee (KAIST Department of Nuclear Quantum Engineering)
Cho, Gyu-Seong (KAIST Department of Nuclear Quantum Engineering)
Kang, Dong-Uk (KAIST Department of Nuclear Quantum Engineering)
Kim, Myung-Soo (KAIST Department of Nuclear Quantum Engineering)
Cho, Min-Sik (KAIST Department of Nuclear Quantum Engineering)
Yoo, Hyun-Jun (KAIST Department of Nuclear Quantum Engineering)
Kim, Ye-Won (KAIST Department of Nuclear Quantum Engineering)
Publication Information
Journal of the Institute of Electronics Engineers of Korea SD / v.49, no.4, 2012 , pp. 7-14 More about this Journal
Abstract
A image quality is limited by a sample-and-hold circuit of the X-ray CMOS image sensor even though simple mos switch or bootstrapped clock circuit are used to get high quality sampled signal. Because distortion of sampled signal is produced by the charge injection from sample-and-hold circuit even using bootstrapped. This paper presents the 3D micro-inductor design methode in the CMOS process. Using this methode, it is possible to increase the ENOB (effective number of bit) through the use of micro-inductor which is calculated and designed in standard CMOS process in this paper. The ENOB is improved 0.7 bit from 17.64 bit to 18.34 bit without any circuit just by optimized inductor value resulting in verified simulation result. Because of this feature, micro-inductor methode suggested in this paper is able to adapt a mamography that is needed high resolution so that it help to decrease patients dose amount.
Keywords
Inductor; High Resolution;
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