Cryogenic Readout Electronics & Technology for FIRST's Stressed Array

Abstract
The ESA satellite "FIRST" (Far Infrared and Submillimeter Space Telescope) is scheduled for launched in 2005. It is a successor to the IRAS and ISO satellites, and it should outperform them in terms of imaging wavelength (the 100 µm to 1 mm band), focal plane size, angular resolution and sensitivity. One major candidate for the focal plane instrument is based on stressed Germanium-Gallium (Ge:Ga) detectors. For low leakage operation, these detectors should be operated at 1.6 Kelvin, and the closely coupled readout electronics should be operated at the same temperature. In this paper we describe the electrical and environmental constraints of the design of the readout electronics for the 16*16 pixel array. These specifications cannot be met with the readout circuits from the earlier ISOPHOT instruments. New circuits and amplification techniques and a new generation of cryogenic CMOS technology is needed.