The detector control unit: an ASIC for the monitoring of the CMS silicon tracker

The detector control unit (DCU) is an ASIC developed as the central building block of a monitoring system for the Tracker of the Compact Muon Solenoid (CMS) experiment. Leakage currents in the Silicon detectors, power supply voltages of the readout electronics and local temperatures will be monitored in order to guarantee safe operating conditions during the 10-years lifetime in the large hadron collider (LHC) environment. All these measurements can be performed by an A/D converter preceded by an analog multiplexer and properly interfaced to the central control system. The requirements in terms of radiation tolerance, low-power dissipation and integration with the rest of the system led to the design of a custom integrated circuit. Its structure and characteristics are described in this paper.