Development of Cryogenic Readout Electronics for Sensitive Far-Infrared Detectors

Abstract

We have successfully developed low-noise, low-power cryogenic readout electronics (CRE) for sensitive far-infrared detectors operated at low temperatures. The CRE must be mounted besides of the detector, and thus, it must be operated at cryogenic temperatures. The reasons of that are to avoid electrical interferences to the high-impedance portion between the detector itself and the CRE, and to minimize the stray capacitance that may decrease the read-out gain. The goals of the CRE performance are the operation temperature can be down to 2K, the noise level is 2µV/√ Hz at 1Hz, the power consumption is 10µW/channel, and the open-loop gain of differential amplifier is over 1000. We have so far manufactured the CRE four times, and evaluated the performances at 4.2K. The present performance achieved is nearly acceptable for the far-infrared sensor of the next Japanese infrared astronomical satellite, ASTRO-F. © 2003, The Institute of Electrical Engineers of Japan. All rights reserved.