DENEB: a 1024-channel cryogenic mixed-signal ASIC for SiPM matrix readout targeting sub-100 ps timing and wide dynamic range

DENEB is a 1024-channel mixed-signal ASIC under development at INFN in 110 nm CMOS technology for the readout of 32×32 silicon photomultiplier (SiPM) matrices over a wide temperature range (77–300 K). It is intended for scintillation-light cameras in single-phase noble-liquid detectors, where charged-particle tracks are reconstructed from scintillation light alone. Each channel comprises a low-impedance input stage, a fast timing branch with dual-threshold discriminators, on-pixel time-to-digital converters, and a charge branch for photon counting based on discrete-time current-to-frequency conversion. The front end targets sub-100 ps single-photon time resolution and a dynamic range exceeding 100 photoelectrons, while supporting per-channel event rates up to a few MHz under stringent power and cryogenic constraints. At the periphery, SRAMs buffer the event words and 32 high-speed SLVS/LVDS transceivers provide an aggregate bandwidth up to ∼ 20 Gbps in double-data-rate mode using time-division multiplexing. Architectural choices are driven by scalability to large channel counts, the need for derandomization to mitigate TDC deadtime, and robustness across the full temperature range. This work presents the system requirements, design strategy, and key architectural features of the DENEB ASIC, including pixel and end-of-column organization, data-readout scheme, and integration aspects at the package and detector level. Design trade-offs and ongoing challenges related to large-channel-count cryogenic operation are discussed, together with the current development status and outlook.