Space based low background infrared measurements present stringent performance requirements on the infrared detector arrays and their associated readout multiplexer circuitry. Very low temperature cryogenics environments (2 Kelvin) are required by these systems to achieve detector performance levels. These cryogenics environments pose technical challenges ont he readout multiplexer performance. Although significant performance improvements have been realized in low noise low temperature readout multiplexers, substantial systems penalties must be paid in the use of elevated temperature stages to operate these devices. This proposed effort will demonstrate that low noise infrared detector array readout multiplexers can be achieved through the use of TRW's advanced cryogenic-Complementary Metal Oxide Semiconductor (cryo-CMOS) fabrication process.Low background infrared systems such as those on the space infrared telescope facility.FPA, infrared, multiplexer, readout, cryogenicSTATUS: Phase I Only