Cryogenic ASICs in GaAs for Applications with Particle Detectors

We present two cryogenic Application Specific Integrated circuits (ASIC's) realized with a GaAs MESFET process. A single-channel differential or double-channel single-ended voltage sensitive preamplifier for 4.2 K operation, to be used with bolometric detectors, was realized and tested. A very simple structure working as a unity gain buffer or as a transconductance amplifier, or even as a shaping filter was tested in view of an application with a fast particle detector operated at liquid Argon temperature