Integrated front-end electronics for single photon time-stamping in cryogenic dark matter detectors

ALCOR is a first prototype of a 32-pixel low-power mixed-signal ASIC developed to readout silicon photomultipliers at low temperature. The chip, designed in 110 nm CMOS technology, performs single photon time-stamping with a maximum event rate of 5 MHz per pixel. The time measurement is performed using low-power TDCs based on analogue time interpolation. The time binning achievable at maximum clock frequency is 50 ps and the target power consumption is less than 5 mW per pixel. Generated data are serialised and transmitted through LVDS drivers. To assert the CMOS electronic behaviour at 77 K, a Test Chip has been produced and tested. Results of a digital synchronisation circuit are reported and discussed.