A mixed signal Multi-Chip Module with high speed serial output links for the ATLAS level-1 Trigger

We have built and tested a mixed signal Multi-Chip Module (MCM) to be used in the Level-1 Pre-Processor system for the Calorimeter Trigger of the ATLAS experiment at CERN. The MCM performs high speed digital signal processing on four analogue input signals. Results are transmitted serially at a serial data rate of 800 MBd. Nine chips of different technologies are mounted on a four layer copper substrate. Analogue-to-digital converters and serialiser chips are the major consumers of electrical power on the MCM, which amounts to 9 Watts for all dies. Special cut-out areas are used to dissipate heat directly to the copper substrate. In this paper we report on design criteria, chosen MCM technology for substrate and die mounting, experiences with the MCM operation and measurement results.