TOPIX: The first prototype of pixel readout for PANDA experiment

The first prototype (TOPIX) of pixel readout has been designed and tested in a first attempt to develop a custom solution for the pixel detector of the PANDA experiment. A small circuit composed of 32 single pixel readout cells was implemented in a 130 nm CMOS process. Each cell is equipped with a preamplifier and a comparator circuit to measure the Time over Threshold (ToT). Several chips were characterized to check the uniformity of the preamplifier response and ToT signal. Total Ionizing Dose (TID) tests at different dose rate and displacement damage test were performed: the results of these measurements are reported in this paper.