Jean Ditta, Nadia Fouque, Valérie Hermel,
Jean Pierre Mendiburu, Jean Pierre Peigneux

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to be submitted
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We have developed a calibration system of the read out chain of the CMS-ECAl, based on the injection of a precise charge pulse at the input of the amplifier. This pulse is ordered in time and amplitude from the control room and is produced by an integrated generator, on the input of each preamplifier. The system is organised around three chips: i) a custom logical controller, developed in laboratory, that selects the relevant information for test pulse and distributes it to the other calibration chips (DAC and injector),  ii)) a commercial DAC, that produces a DC level for the amplitude of the injector and iii)  an injector that build a current pulse having the shape of the APD’s one and the amplitude selected by the DAC. We describe the system, which is still in evolution and the different chips that have been founded in DMILL technology.
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