Characterization of a compact TDC unit with picosecond timing capabilities

High-precision time measurements are the latest trend for particle physics experiments and medical applications (such as PET). Compactness, scalability and applicability to thousands of channels is required for the readout electronics. CAEN A5203 board, part of a synchronizable and distributable Front-End Readout System (FERS), integrates the CERN picoTDC Application-Specific Integrated Circuit (ASIC) into a small unit for high-resolution time measurements of Time of Arrival (ToA) and Time over Threshold (ToT). The performances of the A5203 unit, in terms of time resolution, walk correction, background reduction and signal amplitude reconstruction will be presented. The reported results come from laboratory tests with a signal generator and the A5256 CAEN Adapter, and from the unit application to the Picotech PET system.