LHC1: A semiconductor pixel detector readout chip with internal, tunable delay providing a binary pattern of selected events

Abstract The Omega3/LHC1 pixel detector readout chip comprises a matrix of 128 × 16 readout cells of 50 μ m × 500 μ m and peripheral functions with 4 distinct modes of initialization and operation, together more than 800 000 transistors. Each cell contains a complete chain of amplifier, discriminator with adjustable threshold and fast-OR output, a globally adjustable delay with local fine-tuning, coincidence logic and memory. Every cell can be individually addressed for electrical test and masking. First results have been obtained from electrical tests of a chip without detector as well as from source measurements. The electronic noise without detector is ∼ 100 e − rms. The lowest threshold setting is close to 2000 e − and non-uniformity has been measured to be better than 450 e − rms at 5000 e − threshold. A timewalk of