Characterization of SBRC-190: a multi-gain, cryogenic readout multiplexer for IR detector arrays

SBRC-190 readout multiplexer is a 1×32, multi-gain, capacitive transimpedance amplifier (CTIA) especially suitable for use with infrared detector arrays requiring low-bias levels--such as Ge:Ga far infrared detector arrays. The unit-cell design employs a feedback loop which keeps the bias across the detector constant and, therefore, prevents debiasing--a critical requirement for far infrared detectors. We have tested a number of these multiplexers at various cryogenic temperatures, down to 1.7K. In this presentation we will report the results of our tests and will discuss gain, uniformity, and read noise of the bare mux under correlated-double sampling at 4.2K.