FAST3 ASIC: an analog front-end with 30 ps resolution, designed to readout thin Low Gain Avalanche Diodes

Abstract This contribution presents a new version of the FAST (Fast Amplifier for Silicon detector for Timing) ASICs, called FAST3, and the more significant results from its characterization. The FAST3- Analog version is a 16-channel front-end electronic designed for low power consumption, minimal noise, reduced temporal jitter, and a wide charge input range (3–40 fC). Developed in standard 110 nm CMOS technology, the ASIC is optimized to read out LGAD sensors in timing and tracking applications. The FAST3- Analog was extensively characterized in the laboratory using a low-jitter pulser, a β -source, and during a beam test campaign at DESY. Its performance has been evaluated while coupled with LGADs of different active thicknesses (50 and 80 μm) and pixel capacitances (3.8 and 1.8 pF). Characterization results demonstrated the capability of FAST3 to achieve temporal jitter below 25 ps for charges above 10 fC, and to measure the passage time of charged particles through an LGAD, with a temporal precision of approximately 35 ps.