Pixel electronics for a hybrid x/gamma-ray imager

ABSTRACT The Photon 4–dimensional Digital Information (P4DI) ASIC is a new generation of 2D imaging chips to be connected to a pixel sensor using the bump and flip chip technologies. It gives in digital format energy, time and position information for each recorded event. In pixel digitization and storage of the time and amplitude signal are performed. Circuit solutions for gain and offset variation compensation have been implemented. The ASIC works in sparse data scan mode. An 8x8 pixels prototype has been manufactured in UMC 0.18um CMOS technology and evaluated Keywords: pixel readout electronics, CMOS, ASIC, X/gamma-ray hybrid detectors, time tagging 1. INTRODUCTION Compound semiconductor sensors have emerged as leading candidates in room – temperature, large volume X/Gamma-ray imaging coupled with spectrometry for security 1 , medical 2,3 , industrial 4 and space applications 5,6 . Hybrid Imagers were the sensing layer is made of a pixilated compound semiconductor single crystal have entered not only in the field of scientific instrumentation but also in high market applications with driving force the medical sector