Development of the ABCStar front-end chip for the ATLAS silicon strip upgrade

The ATLAS experiment will build an all-silicon tracker in the Phase II upgrade for the High Luminosity LHC (HL-LHC) at CERN. For the silicon strip detector of the Inner Tracker, a new readout chip ABCStar is under design to cope with the increased occupancies and harsher radiation environment, and to accomodate the new trigger architecture. In this paper, we summarize the status of the design work and present the new features of the chip.