CASAGEM: A readout ASIC for MPGDs

A readout Application Specific Integrated Circuit (ASIC) has developed for neutron Time Project Chamber (nTPC). The nTPC uses Gaseous Electron Multiplier (GEM) for signal multiplication and readout, so we design this ASIC for readout the signals from GEM. The ASIC provides charge amplification and CR-(RC) 5 shaping of the detector signals and buffers them out. It also provides adjustable gain which can be adjusted from 2mV/fC to 40mV/fC and adjustable shaping time which can be adjusted from 20ns to lOOns. So this chip can be applied to detectors with different output signal range and different counting rate. CASAGEM has already been tested; the Integral Nonlinearity Error is no more than 1%. The ASIC is fabricated with Chartered 0.35um CMOS process. More circuit design Details and test results will be presented.