This paper describes a differential readout circuit technique for uncooled Infrared Focal Plane Arrays (IRFPA) sensors. The differential operation allows an efficient rejection of the common-mode noise during the biasing and readout of the detectors. This has been enabled by utilizing a number of blind and thermally-isolated IR bolometers as reference detectors. In addition, a pixel-wise detector calibration capability has been provided in order to allow efficient error corrections using digital signal processing techniques. The readout circuit for a 64×64 test bolometer-array has been designed in a standard 0.35-μm CMOS process. Circuit simulations show that the analog readout at 60 frames/s consumes 30 mW from a 3.3-V supply and results in a noise equivalent temperature difference (NETD) of 125 mK for infrared optics.

Date Published: 6 May 2009
PDF: 8 pages
Proc. SPIE 7298, Infrared Technology and Applications XXXV, 72982F (6 May 2009); doi: 10.1117/12.819826

Published in SPIE Proceedings Vol. 7298:
Infrared Technology and Applications XXXV
Bjørn F. Andresen; Gabor F. Fulop; Paul R. Norton, Editor(s)