Computer simulation of a switched FET readout multiplexer

This paper describes the computer simulation of a hybrid infrared focal plane array (IRFPA) readout multiplexer. The device under study is a switched field effect transistor (SWIFET) readout multiplexer that utilizes a source follower per detector (SFD) unit cell amplifier. The objective of this study is to determine if the limiting component of the IRFPA nonlinearity is the infrared detector array or the readout multiplexer. This study was performed by developing a computer simulation within which the material, fabrication, and operational parameters of the SFD readout multiplexer could be varied. The computer simulation is able to predict experimental data from a SFD readout multiplexer thereby providing validation that the device models used in the computer simulation are correct. The most significant result determined by this study is that the nonlinearity associated with the SFD readout multiplexer is approximately an order of magnitude lower than the nonlinearity from a state-of-the-art PtSi infrared detector array. The nonlinearity in the SFD readout multiplexer is dominated by the body-effect in the source follower amplifiers that comprise the SFD readout multiplexer.