Characterization of the upgraded Frontend Electronics of the Shwarzschild-Couder Telescope based on the SMART ASIC

Abstract

We present the characterization of the new Frontend Electronics (FEE) developed for the Schwarzschild-Couder Telescope (SCT) camera of the CTA experiment. The new FEE is based on a new Application-Specific Integrated Circuit (ASIC) intended to read-out arrays of Silicon Photomultipliers (SiPMs) for low-level light detection down to the single photoelectron, called SMART (SiPM Multichannel ASIC for high Resolution Cherenkov Telescopes). The analog channel is composed of a high speed path with programmable gain and pole-zero filter designed for photon-counting. An external fast digitizer can be used for the photon-counting analysis. A slow path allows the measurement of the mean SiPM current, sampled by an internal 10-bit ADC. We present the characterization results obtained when coupling the SMART to a 16 SiPM matrix produced by Fondazione Bruno Kessler (FBK). Results in terms of charge spectrum, signal-to-noise ratio and dynamic range will be presented. The SMART ASIC was then coupled to the SCT readout electronics based on the TARGET ASICs, able to digitize waveforms at a frequency of 1GS/s and to generate trigger signals. In this work, we further present the preliminary characterization obtained on the full FEE chain.