CASIS: a Very High Dynamic Range Front-End Electronics with Integrated Cyclic ADC for Calorimetry Applications

Following the proposal of satellite-born experiments dedicated to the measurement of the cosmic ray primary flux at the energies of the "knee" (TeV), we designed a new-concept front-end ASIC, CASIS, with an input dynamic range of 50 pC (10000 minimum ionizing particle, MIP). To allow for this very large dynamic range we developed a new Charge Sensitive Amplifier (CSA) architecture, which uses a real-time automatic gain selection circuitry to switch between the input ranges of [0 divide 500 MIP] and [0 divide 10000 MIP]. Following the CSA, a Correlated Double Sampling shaper and a fast (10 MHz clock) Cyclic ADC complete the readout channel. We report on the design and the performances of a six channel prototype that has been realized using a 0.35 mum CMOS technology of Austria Micro Systems.