The SYNC chip in the front-end electronics of the LHCb muon detector

We present a custom integrated circuit, named SYNC, which is a fundamental building block in the front-end architecture of the LHCb muon detector. SYNC is realized in IBM 0.25 mum technology, using radiation hardening layout techniques. Each SYNC integrates the complete front-end L0 stage, consisting of a buffer and a derandomizer and an interface to the L1 stage. It also integrates custom TDCs, one per each input channel, having a time resolution of 1.5 ns. Many monitoring and diagnostic facilities are also integrated on the chip. We describe the circuit architecture, its internal blocks and its main modes of operation.