  Smarty is a fully-reconfigurable on-chip feed-forward artificial neural
network (ANN) with ten integrated time-to-digital converters (TDCs) designed in
a 16 nm FinFET CMOS technology node. The integration of TDCs together with an
ANN aims to reduce system complexity and minimize data throughput requirements
in positron emission tomography (PET) applications. The TDCs have an average
LSB of 53.5 ps. The ANN is fully reconfigurable, the user being able to change
its topology as desired within a set of constraints. The chip can execute 363
MOPS with a maximum power consumption of 1.9 mW, for an efficiency of 190
GOPS/W. The system performance was tested in a coincidence measurement setup
interfacing Smarty with two groups of five 4 mm x 4 mm analog silicon
photomultipliers (A-SiPMs) used as inputs for the TDCs. The ANN successfully
distinguished between six different positions of a radioactive source placed
between the two photodetector arrays by solely using the TDC timestamps.
