LHC1 - A SEMICONDUCTOR PIXEL DETECTOR READOUT CHIP WITH INTERNAL, TUNABLE DELAY PROVIDING A BINARY PATTERN OF SELECTED EVENTS

The Omega3/LHCl pixel detector readout chip comprises a matrix of 128 X 16 readout cells of 50 mu m X 500 mu 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 globall y adjustable delay with local fine-tuning, coincidence logic and memor y. Every cell can be individually addressed for electrical test and ma sking, First results have been obtained from electrical tests of a chi p without detector as well as from source measurements, The electronic noise without detector is similar to 100 e(-) rms. The lowest thresho ld 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 < 10 ns and a precision of < 6 ns rms on a delay of 2 mu s have been me asured. The results may be improved by further optimization.