DIALOG: an ASIC for timing of the LHCb muon detector

The muon detector of the LHCb experiment at CERN plays a fundamental role in the first trigger level. It is mainly realized by means of a multi-wire proportional chambers technology and consists of about 126,000 front-end channels. High efficiency is necessary both at detector and front-end level to satisfy the trigger requirement of five hits per five muon stations with an overall efficiency of 95%. This corresponds to having a single front-end channel detection efficiency of 99% within a time window of 20 ns, and also poses the problem of an accurate time alignment of the whole detector. The problem is addressed by designing two custom integrated circuits, named DIagnostic, time Adjustment and LOGics (DIALOG) and SYNC. DIALOG integrates important tools for detector time alignment procedures and time alignment monitoring on the front-end system. Many other features, necessary for the muon trigger operation and for a safe front-end monitoring, are integrated on DIALOG.