Title
Characteristics of Fault-Tolerant Photodiode and Photogate Active Pixel Sensor (APS)
Abstract
Reliability and manufacturing costs due to defects is a significant problem with image sensors and the ability to recover from a fault would alleviate some of these costs. A fault-tolerant APS has been designed by splitting the APS pixel into two halves operating in parallel, where the photo sensing element has been divided in two and the readout transistors have been duplicated while maintaining a common row select transistor. This split design allows for a self correcting pixel scheme such that if one half of the pixel is faulty, the other half can be used to recover the entire output signal. The fault tolerant APS design has been implemented in a 0.18µm CMOS process for both a photodiode based and photogate based APS. Test results show that the fault tolerant pixels behave as expected where a non-faulty pixel behaves normally, and a half faulty pixel, where one half is either stuck low or high, produces roughly half the sensitivity. The ratios of a normally operating pixel to a faulty pixel show an average value of 2.03 (stuck low) and 1.89 (stuck high) for the photodiode based APS, and 1.73(stuck low) and 1.77 (stuck high) for the photogate based APS. Preliminary results indicatethat the sensitivity of a redundant pixel is approximately three times that of a traditional pixel for the photodiode APS and approximately twice that for the photogate APS.
Year
DOI
Venue
2004
10.1109/DFTVS.2004.1347825
DFT
Keywords
Field
DocType
fault tolerant pixel,active pixel sensor,half faulty pixel,fault-tolerant photodiode,stuck high,traditional pixel,pixel scheme,redundant pixel,faulty pixel,stuck low,non-faulty pixel,aps pixel,image sensor,photodiodes,normal operator,redundancy,fault tolerant,fault tolerance
Computer science,CMOS sensor,Electronic engineering,Cmos process,Real-time computing,Fault tolerance,Redundancy (engineering),Pixel,Transistor,One half,Photodiode
Conference
ISBN
Citations 
PageRank 
0-7695-2241-6
2
0.51
References 
Authors
4
8
Name
Order
Citations
PageRank
Michelle L. La Haye131.60
Glenn H. Chapman216734.10
Cory Jung372.34
Desmond Y. H. Cheung4122.47
Sunjaya Djaja5122.47
Benjamin Wang620.51
Gary Liaw720.85
Yves Audet87413.15