FATIC: an ASIC for Fast Timing Micro-Pattern Gas Detectors

We present the architecture of a multichannel ASIC, called FATIC (FAst Tuning Integrated Circuit), for time measurement, tracking and triggering on signals from an innovative Fast Timing Micropattem (FTM) gaseous detector. The FATIC architecture comprises 32 analog channels, each one composed by a low noise charge sensitive amplifier, a fast discriminator for time measurements, and a shaper and arming discriminator. Each fast comparator output is connected to the dedicated input of a 32-channel TDC that measures the arrival time of the incoming event with a time resolution of 100ps. The front-end amplifier has a programmable gain, recovery time and input signal polarity. The digital logic provides the time measurement, trigger generation, data formatting and data packet transmission with error protection on a 320 Mbps e-link. The digital design is triplicated in order to improve the radiation hardness of the system. In this contribution we describe first the structure of the FTM with its working principle and signal characteristics, followed by the architecture and the operating mode of the FATIC analog channel designed for the read-out of the FTM, which is illustrated with simulations.