On novel front-end electronics for the ATLAS BI RPC upgrade at HL-LHC developed in SiGe BiCMOS technology with a high-resolution rad-hard Time-To-Digital converter embedded

The High Luminosity phase of LHC will require a huge improvement on the ATLAS detector in terms of performance, being the entire apparatus operated in much harsher conditions. The BI project is one of the ATLAS Phase-2 approved upgrades, ensuring the demands coming from the physics for the next 20 years. In this framework, a novel dedicated Front-End electronics has been developed, which exploits a BJT-based preamplifier , a fast discriminator and a high resolution (¡ 100 ps) Time-To-Digital converter in SiGe BiCMOS technology, to vastly enhance the detector rate capability. This front-end electronics is integrated for the first time within the detector Faraday cage, largely reducing the effects of spurious noise and allowing a minimum effective charge threshold on the induced signal of 1-2 fC. The integration of the front-end electronics directly within the detector Faraday cage is also permitted by the low power consumption of 15 mW/ch. The RPC coupled with this novel front-end electronics represents a new generation of large area timing detectors, granting a record time resolution of 350 ps on a single gas gap of 1 mm with 1.2 mm electrodes thickness and operated with the ATLAS standard gas mixture . The effect of the extremely low threshold has also an impact on the gas mixture , enabling the usage of eco-friendly gas mixtures which would not be usable elsewise. The latest performance of this newly developed front-end electronics along with the results achieved with RPC detector coupled with it will be shown.