Title :
An 88dB SNR, 30µm pixel pitch Infra-Red image sensor with a 2-step 16 bit A/D conversion
Author :
Peizerat, Arnaud ; Rostaing, Jean-Pierre ; Zitouni, Noureddine ; Baier, Nicolas ; Guellec, Fabrice ; Jalby, Rémi ; Tchagaspanian, Michael
Author_Institution :
CEA-LETI, Grenoble, France
Abstract :
A new readout IC (ROIC) with a 2 step A/D conversion for cooled infrared image sensors is presented in this paper. The sensor operates at a 50Hz frame rate in an Integrate-While-Read snapshot mode. The 16 bit ADC resolution preserves the excellent detector SNR at full well (~3Ge-). The ROIC, featuring a 320×256 array with 30μm pixel pitch, has been designed in a standard 0.18μm CMOS technology. The IC has been hybridized (indium bump bonding) to a LWIR (Long Wave Infra Red) detector fabricated using our in-house HgCdTe process. The first measurement results of the detector assembly validate both the 2-step ADC concept and its circuit implementation. This work sets a new state-of-the-art SNR of 88dB.
Keywords :
CMOS image sensors; II-VI semiconductors; analogue-digital conversion; cadmium compounds; infrared detectors; mercury (metal); readout electronics; ADC resolution; CMOS technology; HgCdTe; LWIR; ROIC; SNR detector; cooled infrared image sensors; detector assembly; frequency 50 Hz; indium bump bonding; integrate-while-read snapshot mode; long wave infrared detector; readout IC; size 0.18 mum; two step A/D conversion; word length 16 bit; CMOS integrated circuits; Detectors; Dynamic range; Radiation detectors; Random access memory; Signal to noise ratio;
Conference_Titel :
VLSI Circuits (VLSIC), 2012 Symposium on
Conference_Location :
Honolulu, HI
Print_ISBN :
978-1-4673-0848-9
Electronic_ISBN :
978-1-4673-0845-8
DOI :
10.1109/VLSIC.2012.6243823