Low noise 4-channel front end ASIC with on-chip DLL for the upgrade of the LHCb Calorimeter

An integrated circuit for the Upgrade of the LHCb Calorimeter front end electronics is presented. It includes four analog channels, a Delay Locked Loop (DLL) for signal phase synchronization for all channels and an SPI communication protocol based interface. The analog circuit is based on two fully differential interleaved channels with a switched integrator to avoid dead time and it incorporates dedicated solutions to achieve low noise, linearity and spill-over specifications. The included DLL is capable of shifting the phase of the LHC clock (25 ns) in steps of 1 ns. The selected technology is AMS SiGe BiCMOS 0.35 um.