ASIC Front-End for Multianode Photomultiplier based PET systems with Gain Adjustment and Depth of Interaction measurement

We present an improved front-end ASIC architecture which can be used either with Multianode Photomultiplier Tubes or with silicon photomultipliers in a continuous crystal Positron Emission Tomography detector. Gamma-ray impact position and depth of interaction is obtained through a DPC charge division network. A Current Sensitive Preamplifier Stage isolates the PM outputs from the resistor network and introduce a digitally programmable gain adjustment. DOI is calculated from the width of the scintillation light distribution which can be obtained from the sum of anode voltages. A stage of transconductance amplifiers and a high speed current mode adder scheme do the voltage addition operation.