CMOS image sensors are generally considered as being particularly suited to the harsh space environment, if they can get their performance up to the CCD levels. Recent developments indicate however that this object can be achieved.
This paper presents the current state of the art in CMOS Active Pixel Sensors (APS) for space applications at Fillfactory and also highlights some commercial and industrial development that can be of interest for the space community.
PACS covers the wavelength range 80-210 micrometers in spectrometric and photometric imaging modes. The long wavelength camera is a 16 X 25 pixel array of stressed Ge:Ga detectors. In order to demonstrate the feasibility of such a large array, one of the 25 linear arrays was manufactured. It consists of 16 elements of 1.5 mm3 each separated by ceramic plungers and stressed by one single mechanism. As preamplifier a dedicated CMOS circuit was developed, based on similar circuits successfully operating in ISO's photometer. In particular, it was intended to increase the gain of the CRE in order to minimize the debiasing effects on the low bias operated detectors. Two complete linear demonstrator arrays were manufactured and independently tested under various low background conditions in a 1.7 K environment at MPIA and MPE. The feasibility of the concept chosen was demonstrated in several functional tests. Valuable experience was gained to guide the development of the next generation of CREs and arrays.