Design and test of a 64-channel charge measurement ASIC developed in CMOS 0.35 μm technology

A 64-channel charge measurement (Application-Specific Integrated Circuit) ASIC has been designed and tested: it is intended to serve as a front-end electronic read-out for detectors to monitor and measure radiotherapeutical beams. The ASIC has been designed in a CMOS 0.35 μm technology with particular attention to the linearity over a wide input range and can accept currents of both polarities. The linearity is better than 1.5% for a dynamic range of the input current between 500 pA and 3 μA. For a charge resolution of 350 fC, the spread (r.m.s.) of the gain is less than 1%.