Low noise analog CMOS signal processor with a large dynamic range for silicon calorimeters

A low-noise signal processor using CMOS technology is designed for the silicon calorimeter SiCAL of the ALEPH experiment. Modifications are made to the AMPLEX integrated circuit designed for the inner silicon detector of the UA-2 experiment. The output voltage swing has been improved to 6 V. A fast analog summing system, based on the neural network principle, computes the average of charges received at the inputs for trigger generation. The chip contains 16 channels including a charge amplifier, shaper amplifier, track-and-hold stage, multiplexer, fast analog sum and calibration system. The power consumption of the overall chip will be about 100 mW. The predicted equivalent noise charge per channel is 800 erms− plus 20 erms− per pF of input capacitance, and the peaking time is around 300 ns for an input capacitance of 20 to 50 pF.