Dresden 2013 – scientific programme

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HK: Fachverband Physik der Hadronen und Kerne

HK 10: Instrumentation

HK 10.5: Talk

Monday, March 4, 2013, 12:00–12:15, WIL-A221

The GANDALF 128-channel Time-to-Digital Converter — Tobias Baumann, •Maximilian Büchele, Horst Fischer, Matthias Gorzellik, Tobias Grussenmeyer, Florian Herrmann, Phillip Jörg, Paul Kremser, Tobias Kunz, Christoph Michalski, Sebastian Schopferer, and Tobias Szameitat — Physikalisches Institut der Albert-Ludwigs-Universität Freiburg

In particle physics experiments, Time-to-Digital Converters (TDC) perform accurate time measurements, thus to allow for charged particle identification and tracking. We have developed within the GANDALF framework a 128-channel TDC, implemented in a Xilinx Virtex-5 FPGA. A time resolution better than 93 ps has been verified for all channels. In contrast to previous FPGA-based TDC, the design makes use of a shifted clock sampling algorithm. In this concept, the input signal is sampled with flip-flops driven by a set of equidistant phase-shifted clocks. The TDC register length depends only on the number of phase-shifted clocks and therefore permits to process a large number of channels in a very resource-efficient way.

As not only time measurements but also simultaneous rate measurements are required for many applications, we present a combination of 96 scaler and TDC channels implemented in the same FPGA on the GANDALF 6U-VME64x/VXS carrier board. In addition to the experiment trigger, an internal generated pseudo-random trigger is applied in order to produce two independent data streams. This may allow for online monitoring of the detector device. This project is supported by BMBF and EU FP7 (Grant Agreement 283286).