Testing and characterizing the performance of the CRYO ASIC for the nEXO experiment

The next Enriched Xenon Observatory (nEXO) experiment uses a noble liquid time projection chamber detector to search for the neutrinoless double beta decay of Xenon-136. Interactions between double beta decay electrons and liquid xenon within the chamber produce ionization electrons and scintillation photons. The drift of the electrons generate charge signals that need to be amplified, digitized, and recorded. The CRYO ASIC is a system-on-chip waveform digitizer and serializer that is designed to operate at cryogenic temperatures for both the DUNE far detector and nEXO. The pre-amplification stage of the CRYO ASIC has been optimized for the input capacitances of DUNE and nEXO, which are 150 pF and 40 pF respectively. To test the nEXO variant of the CRYO ASIC, we use built-in charge calibrators that create a pulse to mimic a step signal input. The ASIC is tested under different environmental and thermal conditions to achieve a thorough characterization. Test results will be used to assess the functionality and performance of the ASIC and guide the design of future prototypes of the chip.