A digital signal processing module for gamma-ray tracking detectors

We have designed and constructed an 8-channel digital signal processing board for the GRETINA spectrometer. The digitizer samples each of 8 inputs at 100 MHz with 12-bit resolution. Employing a large on-board FPGA, the board derives an energy, leading-edge time, and constant-fraction time from the input signal providing the functionality of a conventional analog electronics system. Readout and control of the digitizer is done over a VME bus. The digitizer's performance met all requirements for processing signals from the GRETINA spectrometer.