Mixed-signal custom integrated circuit development for physics instrumentation

The Monolithic Systems Development Group at the Oak Ridge National Laboratory has been greatly involved in custom mixed-mode integrated circuit development for the PHIENIX detector at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory and position-sensitive germanium spectrometer front-ends for the Naval Research Laboratory (NRL). This paper will outline the work done for both PHENIX and the Naval Research Laboratory in the area of full-custom, mixed-signal CMOS integrated electronics. The PHENIX detector is a large multi-component detector at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. PHENIX has over 400,000 channels of electronics, most of which is implemented using custom integrated circuits. We presently have responsibility for developing and manufacturing electronics for the event vertexfinding subsystem, the pads tracking subsystem, the electromagnetic calorimeter subsystem, and the muon tracking/identification subsystems. We have developed an architecture utilizing simultaneous read-write analog memories used throughout the detector that allows data to be continuously taken even during event readout (a deadtime-less system). The manufacturing technologies being used range from multi-layer printed-circuit boards to multi-layer, multi-chip modules (MCMs). The germanium spectrometer electronics for the Naval Research Laboratory consist of low-noise preamplifier-shapers-peak stretchers and discriminators. The preamplifiers have been optimized for detector capacitances of approximately 10 pF and shaping times of 5-10 .ts. This paper will present the architectures chosen for the various PHENIX detectors which include position-sensitive silicon, capacitive pixel, and phototube detectors, and performance results for the subsystems as well as a system description of the NRL germanium strip system and its performance. The performance of the custom preamplifiers, discriminators, analog memories, analog-digital converters, and control circuitry for all systems will be presented. Keywords: Physics, electronics, CMOS