Presentation of the front-end “ROC” chips readout for ECAL and HCAL ILC

The OMEGA group at LAL has designed 3 chips for the ILC calorimeters. Two are dedicated to the hadronic calorimeters (SPIROC for the analog one and HARDROC for the digital one) and one for the electromagnetic calorimeter (SKIROC). These front-end ASICs must ensure a data format uniformity in all the calorimeters to allow a standardized detector interface board (DIF). The main requirement for data transfer is the minimization of power dissipation as all chips are embedded inside the detector. Data lines must also be minimized as the detector front-end boards need to be abuttable to reach a length of several meters. The readout system is based on the token ring protocol and all critical data lines are doubled for redundancy. The readout and the management of these 3 chips will be explained in detail. A large part of this paper is also dedicated to the Power On Digital (POD) module which is necessary to manage the 40 MHz and 5 MHz clocks during the readout and thus allows to fulfil the 10-25 μW per channel requirement.