A Digital Front-end Readout Mlcrosystem For Calorimeters At LHC

The Front-End Read-out MIcrosystem (FERMI) for calorimeters at LHC presented last year has been further developed with the aim to achieve a full silicon implementation early 1994. Each microsystem will, as before, contain 9 channels with 15-16 bits dynamic range using IO-bit AD converters sampled every 15 ns. The function is accomplished by using a non-linear amplifier in front of the ADC to compress high amplitude signals, reversing the transformation to obtain overall linearity in a look-up table after the digitisation. The direct first-level trigger output for digitally filtered energy data is equipped with pulse recognition capability. The main data flow enters a pipeline memory from which relevant portions are extracted to second and third-level triggers via an adaptive 7-tap digital filter. The module is presently developed as 14 ASICs to be