A cryogenic and low noise front End electronics for high capacitance detector

A cryogenic and low noise front end has been developed first for T2K experiment. The latest developments are aimed for LAGUNA LBNO, which is a long term neutrino project (year 2020). A middle term detector will be build at CERN in 2015. However, the current design is being mounted on a small Time Projection Chamber (TPC) in our laboratory. The identical channel of this 8-channel chip is made of a low noise Charge Sensitive Amplifier (CSA) with respectively 500fF and 2MΩ feedback network (C
_pa
//R
_pa
). The CSA is followed by a 1μs bandpass filter and a buffer line driver. The input referred noise level requires at least 1500 e
^-
rms at -150°C with an input detector capacitance of 250pF. With such performance, the minimal signal of 18000e- (2.88fC) will be correctly measured. This front end is implemented in AMS 350nm CMOS process.