AN ASIC IMPLEMENTATION OF DIGITAL FRONT-END ELECTRONICS FOR A HIGH-RESOLUTION PET SCANNER

An Application Specific Integrated Circuit (ASIC) has been designed an d fabricated which implements many of the current functions found in t he digital front-end electronics for a high resolution Positron Emissi on Tomography (PET) scanner. The ASIC performs crystal selection, ener gy qualification, time correction, and event counting functions for bl ock technology high resolution PET scanners. Digitized x and y positio n, event energy, and time information are used by the ASIC to determin e block crystal number, qualify the event based on energy, and correct the event time. In addition, event counting and block dead time calcu lations are performed for system dead time corrections. A loadable seq uencer for controlling the analog front-end electronics is also implem ented. The ASIC is implemented in a 37,000 gate, 1.0 micron CMOS gate- array and is capable of handling 4 million events/second while reducin g parts count, cost, and power consumption over current board-level de signs.