Report on application specific integrated circuits for relativistic heavy ion detectors

Detector systems for RHIC experiments are invariably going to be large and complex. Thus it behooves the planners to incorporate elements that have little need for adjustment, calibration and correction to the produced data. For example, if power, size and cost considerations permit, time can be digitized directly (i.e. with counters, shift registers, etc.) where no adjustments, calibrations or corrections are required. The circuit either works correctly or not at all. This kind of circuit behavior is extremely valuable in detectors with 105 or more channel elements. In analog to digital conversion applications, direct conversion (i.e. flash ADC) may be prohibitive in cost, size and power. Here major effort must be given to minimize the magnitude of offset and conversion gain variance. Where possible self correction and adjustment should be applied at the subsystem level