A BiCMOS discriminator interface for the SPD

Abstract

A prototype chip for the analogue readout of the SPD in the LHCb Calorimeter is presented. The chip has been designed using the 0.8mm-BiCMOS technology of AMS and optimised for minimum size and maximum performance at the required frequency of operation in LHC experiments. It consists of a dual structure formed by two integrators, two track and hold circuits, two substractors, two comparators and a multiplexer. The die size occupied by one discriminator circuit is approximately 1720 mm x 330 mm.