Current Input Extended Counting ADC With Wide Dynamic Range for LWIR FPAs

Author

Woo, D.H. ; Kim, C.B. ; Lee, H.C.

Author_Institution

Sch. of Inf., Commun. & Electr. Eng., Catholic Univ. of Korea, Seoul

Volume

9

Issue

4

fYear

2009

fDate

4/1/2009 12:00:00 AM

Firstpage

441

Lastpage

448

Abstract

A readout circuit incorporating a pixel level analog-to-digital converter (ADC) is studied for 2-D long wavelength infrared focal plane arrays (LWIR FPAs). The charge handling capacity of the unit cell circuit is improved by using the current input incremental ADC. The proposed pixel level ADC is based on an extended counting ADC but is composed of two oversampling conversions. The readout circuit has been fabricated using a 0.35 mum 2-poly 4-metal CMOS process for a 128 times 128 LWIR HgCdTe array with a pixel size of 50 mum times 50 mum. The peak signal-to-noise ratio (S/N) and dynamic range (DR) were measured to be 85.8 dB and 99.9 dB, respectively, with a total power consumption of 50 mW.

Keywords

analogue-digital conversion; digital readout; focal planes; 2D long wavelength infrared focal plane arrays; LWIR FPA; charge handling capacity; current input extended counting ADC; current input incremental ADC; noise figure 85.8 dB; noise figure 99.9 dB; oversampling conversions; pixel level analog-to-digital converter; power 50 mW; readout circuit; Analog-digital conversion; CMOS process; Circuit noise; Dynamic range; Noise reduction; PSNR; Power measurement; Signal processing; System-on-a-chip; Temperature; Extended counting ADC; infrared focal plane array; pixel level analog-to-digital converter (ADC); readout circuit; wide dynamic range (DR);

fLanguage

English

Journal_Title

Sensors Journal, IEEE

Publisher

ieee

ISSN

1530-437X

Type

jour

DOI

10.1109/JSEN.2008.2012198

Filename

4797916