Buffered infrared detector array interfacing

Abstract

New results from buffered interfacing techniques used with short-wavelength IR photodiode arrays at room temperature are presented and analyzed. Performance of linear Ge and InGaAs arrays is shown not to be limited by detector characteristics at room temperature, but instead by on-focal-plane hybrid interfacing electronics. Two key issues associated with Si complementary metal-oxide semiconductor (CMOS) interfacing circuitry are input offset voltage, which results in excessive dark currents, and input voltage noise with excessive 1/f characteristics. An analysis of white and 1/f noise generated by both detector and preamplifier is presented. Improved noise performance models give excellent agreement with experimental data. Proposed improvements in readout electronics will result in improved sensitivity and will relax costly cooling requirements associated with detectors.