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In the Name of GOD advanced VLSI class presentation. CMOS IMAGE SENSOR. SEIED MANOOCHEHR HOSEINI University of TEHRAN-IRAN Supervisor : Dr. FAKHRAEI . Applications . The imaging system. [1]. FILL Factor.
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In the Name of GOD advanced VLSI class presentation CMOS IMAGE SENSOR SEIED MANOOCHEHR HOSEINI University of TEHRAN-IRAN Supervisor : Dr. FAKHRAEI
FILL Factor Optically Sensitive Area ~30% of Total Pixel Area [3]
10.0 5.6um (0.3M pixel) 5.0 3.8um (1.3M pixel) 4.0 2.8um (2M pixel) Pixel pitch, um 3.0 2.2um (7.2M pixel) 2.0 < 1.8um < 1.5um This Work 1.0 ’02 ’03 ’04 ’05 ’06 ’07 ’08 Year CMOS Image Sensor Trend [2]
Sum of signal = Sum of noise = By pixel summation SNR increase by 3dB [2]
By clumn wise averanging SNR increase by 3dB Average signal = Average noise = Savg Ramp Gen. Savg [2]
Old and new GNOX process; improvement of random noise by reducing the trap effect on SF transistor. [2],[4]
Increase light gathering power by 20% pixel height shrink [2]
Implementation of average filter by MATLAB software Use average filtering Original image
Implementation of average filter by MATLAB software Use average filtering Original image
4-shared pixel architecture High fill factor (57%) • with SNR max of 41dB under the full-resolution operation. • Pixel level charge summation • Increase 6dB in SNR • Noise reduction technology • SF trap treatment to reduce 1/f noise
REFRENSES [1] A. El Gamal and H. Eltoukhy, “CMOS Image Sensor,” IEEE Circuit and Devices Magazine, vol. 21, no. 3, pp. 6-20, May-June, 2005. [2] Young Chan Kim, Yi Tae Kim, Sung Ho Choi, Hae Kyung Kong, Sung In Hwang, Ju Hyun Ko, Bum Suk Kim, Tetsuo Asaba, Su Hun Lim, June Soo Hahn, Joon Hyuk Im, Tae Seok Oh, Duk Min Yi, Jong Moon Lee, Woon Phil Yang, Jung Chak Ahn, Eun Seung Jung, Yong Hee Lee. Samsung Electronics, Kiheung, Korea “1/2-inch 7.2MPixel CMOS Image Sensor with 2.25µm Pixels Using 4-Shared Pixel Structure for Pixel-Level Summation .” ISSCC 2005. [3] CMOS Image Sensors : Lenses and Filters on Silicon // Lindsay Grant, ST Microelectronics Robert Henderson, University of Edinburgh [4] J.Y. Kim, et al., “Characterization and Improvement of Random Noise in 1/3.2” UXGA CMOS Image Sensor with 2.8µm Pixel using 0.13µm Technology,” IEEE Charge-Coupled Devices and Advanced Image Sensors, pp. 149-152, 2005.