Digital output ROIC with single slope ADC for cooled infrared applications
The objective of this research is to develop an ADC stage integrated into ROIC which enables ROIC to have digital output. Digital output method isolates noise caused by outside mediums. At the system level, removal of the ADC proximity card reduces system complexity and volume of the IDDCA system which is important for avionic and missile applications. It also reduces the system cost associated with external ADC components. A digital output ROIC utilizing single slope ADC is fabricated using 0.18 µm CMOS technology. ADC has been proven to be functional, and infrared images are sampled with the fabricated ROIC and a LWIR detector. Implemented ADC has 12 bits of resolution supporting 27 kS/s sampling speed. It also has programmable high speed mode that extends readout speed to more than 100 kS/s with 10 bits resolution or 50 kS/s with 11 bits resolution. Power consumption is less than 40 µW per column ADC.
The author would like to thank ASELSAN INC (Ankara, Turkey) for their financial support for this work. Fatih Akyurek also acknowledges Turkish Scientific and Technological Research Council (TUBITAK) for providing scholarship for the duration of this work.
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