Integration of ECAL On-Detector Electronics

The on-detector electronics has been designed to read a complete trigger tower including all the necessary services. The trigger tower electronics consists of 5 Very Front End (VFE) boards, 1 Front End (FE) board, 1 Low Voltage Regulator card and a mother board. The low voltage is stabilized in the LVR card and distributed to the FE card and to the VFE cards. The high voltage (HV) for the APDs is directly connected to the mother board. Special flexible Kapton PCBs connect the APDs and the temperature sensors positioned on the crystals to the VFE card connector on the mother board. The FE card is connected to the data acquisition system through two high speed optical data links, one for the trigger and one for the data. It is part of a control ring which is connected by a token ring board to a control fiber ribbon.