Low noise front end ICECAL ASIC for the Upgrade of the LHCb Calorimeter

A fully differential ASIC with cooled input termination is presented as a solution for the Upgrade of the Calorimeter front end electronics. The LHCb experiment needs to increase about ten times the integrated luminosity in order to study new physics. The increase in signal has to be compensated reducing the gain of the photomultipliers which implies stringent noise requirements. The proposed solution offers an active termination at the input and avoids the noise originated by the use of a resistor. The circuit is based on a two interleaved channel with a first amplifier stage, a switched integrator, and a Track-and-Hold. Two prototypes have been implemented and tested in SiGe BiCMOS 0.35um technology.