An Integrated Circuit for Signal Processing of the Ams Rich Photomultiplier Tubes

An analog integrated circuit has been designed, in a BiCMOS 0.8 micron technology, for the feasability study of the signal processing of the AMS RICH photomultiplier tubes [1]. This low power, three channel gated integrator includes its own gate generator and no external analog delay is required. It processes PMT pulses over a dynamic range of 100. An external RC network allows it to work with various PMT gains. It provides a logic output that indicates whether the associated analog output has to be considered. This gated integrator is used with a compact DSP based acquisition system in a 132 channel RICH prototype. The charge calibration of each channel of the RICH is carried out using the light of a LED. The pedestal measurement is performed on activation of a dedicated input. The noise contribution study of the input RC network and of the amplifier's is presented.