Novel high uniformity readout circuit allowing microbolometers to operate with low noise

Author

Lv, Jian ; Zhou, Yun ; Liao, Baobin ; Jiang, Yadong

Author_Institution

State key Lab. of Electron. Thin Film & Integrated Devices, Univ. of Electron. Sci. & Technol. of China, Chengdu, China

fYear

2011

fDate

25-28 Oct. 2011

Firstpage

621

Lastpage

624

Abstract

The capacitive transimpedance amplifier (CTIA) is usually taken as a preamplifier circuit for uncooled microbolometer due to it´s excellent bias control, high injection efficiency, linearity, and noise performance. However, the nonzero input offset voltage in the operational amplifier will cause a significant spatial non-uniformity. In this paper, we have developed a novel CTIA for uncooled microbolometers with correlated double sampling technique. The proposed CTIA suppresses the offset voltage and flicker noise of the op-amp. It improves the readout uniformity and also the temporal noise performance. A 320 × 240 uncooled microbolometer focal plane array based on the proposed circuit was implemented on silicon using a 0.5μm CMOS technology. A thermal IR image is, thus, obtained for F/1 optics and at 60 Hz frame rate. The test spatial fixed pattern noise voltage and temporal root mean square (RMS) noise voltage are 0.0286 V, 546μV, respectively.

Keywords

CMOS analogue integrated circuits; bolometers; infrared imaging; operational amplifiers; readout electronics; CMOS technology; bias control; capacitive transimpedance amplifier; correlated double sampling technique; flicker noise suppression; frequency 60 Hz; injection efficiency; nonzero input offset voltage; offset voltage suppression; op-amp; operational amplifier; preamplifier circuit; readout uniformity improvement; silicon; size 0.5 mum; temporal noise performance; temporal root mean square noise voltage; test spatial fixed pattern noise voltage; thermal IR image; uncooled microbolometer focal plane array; uniformity readout circuit; voltage 0.0286 V; voltage 546 muV; Bolometers; Silicon;

fLanguage

English

Publisher

ieee

Conference_Titel

ASIC (ASICON), 2011 IEEE 9th International Conference on

Conference_Location

Xiamen

ISSN

2162-7541

Print_ISBN

978-1-61284-192-2

Electronic_ISBN

2162-7541

Type

conf

DOI

10.1109/ASICON.2011.6157282

Filename

6157282