Cryogenic CMOS-based control system

This article describes the design and evaluation of a CMOS-based control system for use in cryogenic vacuum environments. A control system, with accompanying software, was designed to interface superconductive digital and sensor circuits in a cryocooler to portable computers at room temperature. It is designed to operate as close as possible to the superconductors to reduce thermal noise. The controller connects via a fibre optical RS-232 interface to any USB connector on a computer at a data rate of 1 Megabaud. The interface to the superconductor electronics consists of 16-bit ultra low-noise ADCs and DACs. Extensive research and testing was done on all components - both active and passive - to validate operation at 60 K. An integrated temperature control system was designed to ensure a stable temperature environment. Results are shown and discussed.