Title :
A double-delta compensating technique for pulse-frequency modulation CMOS image sensor
Author :
Tsung-Hsun Tsai ; Hornsey, Richard
Author_Institution :
Dept. of Comput. Sci. & Eng., York Univ., Toronto, ON, Canada
Abstract :
We design a double-delta compensating (DDC) technique for a comparator-based pulse-frequency modulation (PFM) pixel. This technique has been demonstrated by simulation to achieve both fixed-pattern noise (FPN) reduction and dynamic range (DR) extension at the high-light region. According to the result, the pixel DR extends by at least 12 dB; FPN is reduced from unacceptable levels to 1-3% when it is caused by the comparator offset voltage or less than 3.5% when the layout and process variations are considered. These simulations have been performed using the Monte Carlo method for realistic parameter variations in a 0.18-μm CMOS technology.
Keywords :
CMOS image sensors; Monte Carlo methods; PWM power convertors; comparators (circuits); delta modulation; modulators; pulse frequency modulation; CMOS image sensor; DDC technique; DR extension; FPN reduction; Monte Carlo method; PFM pixel; comparator offset voltage; double-delta compensating technique; dynamic range extension; fixed-pattern noise reduction; pulse-frequency modulation; size 0.18 micron; CMOS image sensors; Dynamic range; Layout; Modulation; Switches; Switching circuits; Transistors;
Conference_Titel :
Electronics, Circuits and Systems (ICECS), 2012 19th IEEE International Conference on
Conference_Location :
Seville
Print_ISBN :
978-1-4673-1261-5
Electronic_ISBN :
978-1-4673-1259-2
DOI :
10.1109/ICECS.2012.6463505
