Design of GaN based Comparator Circuit for Radiation Detectors

GaN HEMT transistors has significant advantage over conventional silicon counterpart, operating in radiation environment. In particle radiation therapy electronic devices are exposed to radiation which degrades their reliability. This paper aims to design a GaN based comparator circuit which is an essential circuit of the front end of radiation detectors used in particle radiation therapy. The circuit is designed using EPC8002 GaN transistors and the simulation results show that it can operate at high frequency (>20MHz) with the propagation delay of less than 1ns. The designed circuit is also tested with the output obtained from H8500 position sensitive photomultiplier tube and simulation result shows the satisfactory output from the comparator.