Title :
Current-mode CMOS image sensor using lateral bipolar phototransistors
Author :
Huang, Ying ; Hornsey, Richard I.
Author_Institution :
Rockwell Semicond., Thousand Oaks, CA, USA
Abstract :
A current-mode image sensor has been designed using current mirrors with amplifying device ratios. Prototype sensors have been fabricated in a standard 0.18-μm CMOS technology. Image capture is demonstrated from two 70 × 48 pixel arrays, using photodiodes and lateral bipolar phototransistors as the photodetectors. The latter type displays a reduced fixed pattern noise, while linearity is similar to that of the photodiode pixel. The lateral bipolar phototransistor pixels also show a greater response in the red region of the visible spectrum.
Keywords :
CMOS image sensors; bipolar transistors; current mirrors; current-mode circuits; photodetectors; phototransistors; active pixel sensors; amplifying device ratios; current amplification schemes; current mirrors; current-mode CMOS image sensor; image capture; lateral bipolar phototransistors; linearity; photodetectors; red region response; reduced fixed pattern noise; spectral response comparison; CMOS image sensors; CMOS technology; Displays; Image sensors; Mirrors; Photodetectors; Photodiodes; Phototransistors; Pixel; Prototypes;
Journal_Title :
Electron Devices, IEEE Transactions on
DOI :
10.1109/TED.2003.820123
