Characterization of the STS/MUCH-XYTER2, a 128-channel time and amplitude measurement IC for gas and silicon microstrip sensors

New physics experiments at the Facility for Antiproton and Ion Research (FAIR) in Darmstadt require application-optimized detector readout circuits. The STS/MUCH-XYTER2 (or SMX2) is a new, 128-channel prototype ASIC for silicon strip detectors and gas electron multiplier (GEM) detectors in the Compressed Baryonic Matter (CBM) experiment. It provides self-triggered amplitude and time measurement of incoming charge and serial streaming of digitized data. The 10 mm × 6.75 mm chip was fabricated employing the UMC CMOS 180 nm process. It comprises of an analog front-end with dual-path processing including a timing comparator in one path and a continuous-time 5-bit analog-to-digital converter in the other path, a digital back-end with time pre-sorting, advanced monitoring and throttling features and multiple 320 Mbps, serial links targeted for a GBT-based data acquisition structure. Specific conditions of the detector systems will be discussed prior to the structure and the features of the ASIC together with measurement results.