Title :
Current-mediated, current-reset 768/spl times/512 active pixel sensor array
Author :
McGrath, R.D. ; Clark, V.S. ; Duane, P.K. ; McIlrath, L.G. ; Washkurak, W.D.
Author_Institution :
Polaroid Corp., Cambridge, MA, USA
Abstract :
A current-mode active pixel sensor (APS) architecture provides an alternative to voltage-mediated source-follower APS devices, offering an architecture that can be built in a digital CMOS technology with fewer FETs in the pixel and readout, fewer bus lines strapping the array and less clocking required for operation. A current-reset approach reduces fixed-pattern noise due to FET performance variations. The architecture is robust with respect to the process-induced variations in a digital process, though this comes at the expense ofincreased power consumption during current reset. A current-mode APS CMOS image sensor with a 768-by-512 array of 15/spl mu/m/sup 2/ pixels is presented in a photographic mode that demonstrates the device variable electronic shutter operation, the x-y addressable nature ofthe circuit, and the inherent antiblooming.
Keywords :
CMOS digital integrated circuits; image sensors; integrated circuit noise; sensor fusion; 393216 pixel; 512 pixel; 768 pixel; FET performance variations; antiblooming; clocking; current reset; current-mode active pixel sensor; current-reset approach; digital CMOS technology; fixed-pattern noise; photographic mode; power consumption; process-induced variations; sensor array; variable electronic shutter operation; x-y addressable nature; CMOS image sensors; CMOS technology; Clocks; Energy consumption; FETs; Noise reduction; Noise robustness; Pixel; Sensor arrays; Voltage;
Conference_Titel :
Solid-State Circuits Conference, 1997. Digest of Technical Papers. 43rd ISSCC., 1997 IEEE International
Conference_Location :
San Francisco, CA, USA
Print_ISBN :
0-7803-3721-2
DOI :
10.1109/ISSCC.1997.585325