A1702

The A1702 Front-End Board is a custom design developed by the Albert Einstein Center for Fundamental Physics of the University of Bern for the readout of SiPM arrays used in the Cosmic Rays veto of Liquid Argon Neutrino Experiments. The board is designed for the exact purpose of detecting coincidences at the far ends of scintillating fibers coupled with SiPMs and measure the signal energy as well as the time of arrival for track reconstruction.
A desktop version DT5702 is also available.

The analog input signal is processed by CITIROC, a 32-channel ASIC from WeeROC. Each channel is made of a high-gain charge preamplifier (x 10 – x 600 gain range), fast shaping with the shaping time of 15 ns and slow shaping with configurable shaping time in the range of 12.5 ns to 87.5 ns. Signals from the fast shapers are discriminated (programmable threshold) and produce digital signals (T0-T31) for event triggering. These signals are then combined in the FPGA to give coincidence triggers. The input signals height can be stored in the ASIC Sample-and-Hold (S/H) circuit and multiplexed to a single analog output. This output is routed to an external ADC for sampling and energy list decoding.

The board allows to perform timing measurements, thanks to external reference signals to be fed at the dedicated LEMO inputs. Using very stable signals, like PPS pulses, it is possible to reach timing resolution down to 1 ns. Additional T-IN/T-OUT connectors for board-to-board trigger validation are also available.

The board communicates with the host computer through Ethernet protocol, relying on a ROOT-based demo software running on Linux.