A multi-functional front end readout electronics system for PET detector application

A compact, 96-ch, multi-functional and practical front-end readout electronics system for a SiPM based PET detector is developed. This electronics system is based on the latest Sigma Delta Modulation (SDM) circuit, which implements a charge-to-digital conversion (QDC) that keeps energy, timing information. In order to achieve a compact size, the system has a stacked structure including two kinds of boards, analog board and digital board. The analog board is responsible for charge integration of SDM while the digital board is for discharging feedback of the SDM circuit. Also, the digital board is applied for energy calculation, timing pickoff and data buffering and transferring. In comparison to the initial version of the SDM QDC, the input signal polarity on the electronics system is improved from negative only to both positive and negative polarities so that it can process both SiPM anode and cathode signals. Several SiPM based PET detectors are applied to validate the capability of dual polarity readout and multi-functionality. Overall, the prototype electronics system demonstrated its good performance for PET application.