A low power time-to-digital-converter in 0.13µm CMOS with 100ps time resolution capability for silicon pixel radiation detector

This paper describes the design of a pixel cell optimized for good time resolution (100ps rms) and high event rate (150kHz per pixel). The key constraints are a maximum power consumption of 1mW per pixel and a 300μm × 300μm cell size. The pixel architecture is based on a preamplifier followed by a Constant Fraction Discriminator (CFD) in order to keep the time resolution against time walk variations. The time measurement is performed inside each pixel by a Time to Digital Converter (TDC) based on time to amplitude conversion. The development is part of the R&D activity for the beam spectrometer, called Gigatracker (GTK), of the NA62 Experiment at CERN.