A BICMOS discriminator interface for the SPD

A prototype chip for the analogue readout of the SPD in the LHCb Calorimeter is presented.The chip has been designed using the 0.8m-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 m x 330 m.