Development of a wide-dynamic range Front-End ASIC for W + Si calorimeter

A Front-End ASIC for a W + Si electromagnetic colorimeter has been developed in a 0.25 μm CMOS process. This calorimeter is proposed to measure prompt γ and π⁰ in a wide energy range at forward rapidity region in high energy p + p and p + Pb collisions at LHC. The prototype ASIC consists of a current conveyor with 4 gain outputs in a first stage to achieve a large dynamic range from 10 fc to 200 pC. Simulation studies show that the linearity is less than 1% for the range of 10⁴. The prototype ASIC chip, which contains 6 input channels, was fabricated and some performance tests were conducted. In this report, design of the ASIC is described and performance obtained from simulations and the prototype chip are summarized.