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Author Tsung-Hsun Tsai ♦ Ching-Chun Wang
Source IEEE Xplore Digital Library
Content type Text
Publisher Institute of Electrical and Electronics Engineers, Inc. (IEEE)
File Format PDF
Copyright Year ©2009
Language English
Subject Domain (in DDC) Technology ♦ Engineering & allied operations ♦ Applied physics
Subject Keyword CMOS image sensors ♦ Dynamic range ♦ Pixel ♦ Sensor arrays ♦ Signal processing ♦ Counting circuits ♦ CMOS process ♦ Fabrication ♦ Photodiodes ♦ Testing
Abstract A development of in-pixel dynamic range (DR) increasing technique without charging extra power for CMOS image sensor was realized in this paper. Recently, many researches reported that high dynamic range can be achieved through processing the image signals with ADCs or counters built inside the pixel, and some other methods require adjustable circuit block to maneuver photo-generated charges by a longer integration time. However, the inevitable consumption of power due to additional circuits alleviates the practicality. In this paper, a CMOS image sensor based on 3T active pixel sensor (APS) with 5.5 µm pixel pitch is investigated, successfully increasing DR without charging additional power by implementing a total of 4 sets of image arrays, of which 3 are new designs and one is typical type as control group. The arrays are 32 × 32 pixels, implemented in a 0.18 µm CMOS fabrication process, where photodiode has an n-well and p-substrate structure. Testing result is an increment of DR by estimated 7 to 18 dB among the experimental groups with no power consumption. The idea of in-pixel DR enhancement technique is verified, and one conclusion is made that in-pixel analog design is one direction for designers.
Description Author affiliation: Department of Electrical Engineering, National Cheng Kung University, Tainan City, Taiwan 701 (Ching-Chun Wang) || Department of Computer, Science & Engineering, York University, Toronto, ON, Canada M3J1P3 (Tsung-Hsun Tsai)
ISBN 9781424445486
ISSN 19300395
Educational Role Student ♦ Teacher
Age Range above 22 year
Educational Use Research ♦ Reading
Education Level UG and PG
Learning Resource Type Article
Publisher Date 2009-10-25
Publisher Place New Zealand
Rights Holder Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Size (in Bytes) 799.60 kB
Page Count 4
Starting Page 1644
Ending Page 1647

Source: IEEE Xplore Digital Library