The DIALOG chip in the front-end electronics of the LHCb Muon detector

We present a custom integrated circuit, named DIALOG (DIagnostic, time Adjustment and LOGics), which is a fundamental building block in the front-end architecture of the LHCb Muon detector. DIALOG is realized in IBM 0.25 mu m technology, using radiation-hardening layout techniques. DIALOG integrates important tools for detector time alignment procedures and time alignment monitoring on the front-end system. In particular, it integrates 16 programmable delays, which can be regulated in steps of 1 us. Other features, necessary for the Muon trigger operation and for a safe front-end monitoring are integrated into DIALOG. It generates the information, that will be used by the trigger, as a combination of its 16 inputs from the Amplifier-Shaper-Discriminator (ASD) chips, it generates the thresholds of the ASD, it monitors the rate of all its input channels. We describe the circuit architecture, its internal blocks and its main modes of operation. Measurements performed on final prototypes are also reported.