  The signal digitization for CROSS, a bolometric experiment for the search of
neutrinoless double beta decay at LSC - Canfranc Underground Laboratory, will
be based on a custom solution comprised of an analog-to-digital board
interfaced to an Altera Cyclone V FPGA module. Each analog-to-digital board
hosts 12 channels that allow data digitization up to 25 ksps per channel and an
effective resolution of 21 bits at the typical sample rate required by the
experiment (5 ksps). The board also allows to digitally select the cut-off
frequency of the anti-aliasing filter with 10 bit resolution from 24 Hz up to
2.5 kHz, as required by fast scintillating bolometers. The FPGA is responsible
for the synchronization of the analog-to-digital boards and for the data
transfer to the storage, using UDP protocol on a standard Ethernet interface.
Each FPGA can manage the data coming from 8 boards (96 channels), allowing an
excellent scalability. In this contribution we will present a complete overview
of the system, and a detailed characterization of the system performance.
