DYNAMIC RANGE EXTENSION OF CMOS IMAGE SENSORS USING MULTI-INTEGRATION TECHNIQUE WITH COMPACT READOUT

2013 ◽  
Vol 22 (06) ◽  
pp. 1350042 ◽  
Author(s):  
ZHIYUAN GAO ◽  
SUYING YAO ◽  
JIANGTAO XU ◽  
CHAO XU

A multi-integration technology with compact readout method to extend CMOS image sensor's dynamic range is presented. Compared with the timing of rolling readout, compact readout extends the available pixel readout time by adjusting the time-domain offset between two adjacent rows and each integration time in one frame. Thus the column readout bus is working continuously rather than intermittently, which makes good use of the whole integration time and the available readout time can be extended. This dynamic range extension technology was implemented on a prototype chip with a 128 × 128 pixel array. The pixel readout time with compact readout method is almost as 3 times long as the one with rolling readout method while 39 dB dynamic range extension is achieved at 120 fps.

2015 ◽  
Vol 15 (6) ◽  
pp. 3265-3273 ◽  
Author(s):  
Zhiyuan Gao ◽  
Suying Yao ◽  
Congjie Yang ◽  
Jiangtao Xu

1995 ◽  
Vol 12 (2) ◽  
pp. 227-238 ◽  
Author(s):  
A. M. Burgess ◽  
R. W. Hunstead

AbstractRadio snapshot imaging is an efficient observing method which allows several sources to be observed in the one session. Snapshot observing with the Australia Telescope Compact Array (ATCA) involves special difficulties, as the small number of antennas combined with the short total integration time leads to high sidelobe levels in the raw images. The images can be improved markedly by standard deconvolution techniques, but more care is required in their use because of the difficulty in distinguishing real emission from artefacts. This study, based on a set of snapshot observations of strong sources at 5 GHz, gives guidance on both the planning of observations and the data reduction. We show that snapshot imaging with the 6 km ATCA can achieve a dynamic range of 100–200:1 provided certain conditions are met, namely a peak flux density > 100 mJy, an angular size ≤ 30″ and an hour-angle coverage spanning at least six well-separated 5-minute cuts. When observing weak sources it is essential for calibration sources to be selected carefully and observed frequently.


Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5447
Author(s):  
Calvin Yi-Ping Chao ◽  
Shang-Fu Yeh ◽  
Meng-Hsu Wu ◽  
Kuo-Yu Chou ◽  
Honyih Tu ◽  
...  

In this paper we present a systematic approach to sort out different types of random telegraph noises (RTN) in CMOS image sensors (CIS) by examining their dependencies on the transfer gate off-voltage, the reset gate off-voltage, the photodiode integration time, and the sense node charge retention time. Besides the well-known source follower RTN, we have identified the RTN caused by varying photodiode dark current, transfer-gate and reset-gate induced sense node leakage. These four types of RTN and the dark signal shot noises dominate the noise distribution tails of CIS and non-CIS chips under test, either with or without X-ray irradiation. The effect of correlated multiple sampling (CMS) on noise reduction is studied and a theoretical model is developed to account for the measurement results.


2009 ◽  
Author(s):  
Leo H. C. Braga ◽  
Suzana Domingues ◽  
José G. Gomes ◽  
Antonio C. Mesquita

Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1096
Author(s):  
Alessandro Michel Brunetti ◽  
Bhaskar Choubey

Extending CMOS Image Sensors’ dynamic range is of fundamental importance in applications, such as automotive, scientific, or X-ray, where a broad variation of incoming light should be measured. The typical logarithmic pixels suffer from poor performance under low light conditions due to a leakage current, usually referred to as the dark current. In this paper, we propose a logarithmic pixel design capable of reducing the dark current through low-voltage photodiode biasing, without introducing any process modifications. The proposed pixel combines a high dynamic range with a significant improvement in the dark response compared to a standard logarithmic pixel. The reported experimental results show this architecture to achieve an almost 35 dB improvement at the expense of three additional transistors, thereby achieving an unprecedented dynamic range higher than 160 dB.


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