Time domain analogue to digital conversion in a digital pixel sensor array

Author

Kitchen, Alistair ; Bouzerdoum, Abdesselam ; Bermak, Amine

Author_Institution

Sch.of Eng. & Math., Edith Cowan Univ., Joondalup, WA, Australia

fYear

2004

fDate

28-30 Jan. 2004

Firstpage

108

Lastpage

112

Abstract

This paper presents a digital pixel sensor array, in which the photodiode sensor, the analogue to digital conversion circuitry, and an 8-bit memory are combined in the 45 /spl mu/m/spl times/45 /spl mu/m pixel, yielding a 12% fill factor. The conversion is performed by measuring the time taken for the photodiode, operating in direct integration mode, to discharge from its reset voltage to a reference voltage. An on chip control circuit is used to compensate for the non-linear relationship between the photocurrent and the integration time. The 64/spl times/64 pixel array is manufactured using a standard 0.35 /spl mu/m, five metal, digital CMOS process.

Keywords

CMOS image sensors; analogue-digital conversion; array signal processing; discharges (electric); photodiodes; photoemission; system-on-chip; time-varying networks; 8 B; digital CMOS process; digital complementary metal-oxide-semiconductor process; digital pixel sensor array; direct integration mode operation; integration time; nonlinear relationship compensation; on-chip control circuit; photocurrent; photodiode sensor; time domain analogue-to-digital conversion; voltage discharges; CMOS process; Integrated circuit measurements; Manufacturing processes; Performance evaluation; Photoconductivity; Photodiodes; Semiconductor device measurement; Sensor arrays; Time measurement; Voltage;

fLanguage

English

Publisher

ieee

Conference_Titel

Electronic Design, Test and Applications, Proceedings. DELTA 2004. Second IEEE International Workshop on

Conference_Location

Perth, WA, Australia

Print_ISBN

0-7695-2081-2

Type

conf

DOI

10.1109/DELTA.2004.10007

Filename

1409825