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arXiv · 1105.1832

TARGET: A multi-channel digitizer chip for very-high-energy gamma-ray telescopes

K. Bechtol·S. Funk·A. Okumura·L. Ruckman·A. Simons·H. Tajima·J. Vandenbroucke·G. Varner
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Abstract

The next-generation very-high-energy (VHE) gamma-ray observatory, the Cherenkov Telescope Array, will feature dozens of imaging atmospheric Cherenkov telescopes (IACTs), each with thousands of pixels of photo-sensors. To be affordable and reliable, reading out such a mega-channel array requires event recording technology that is highly integrated and modular, with a low cost per channel. We present the design and performance of a chip targeted to this application: the TeV Array Readout with GSa/s sampling and Event Trigger (TARGET). This application-specific integrated circuit (ASIC) has 16 parallel input channels, a 4096-sample buffer for each channel, adjustable input termination, self-trigger functionality, and tight window-selected readout. We report the performance of TARGET in terms of sampling frequency, power consumption, dynamic range, current-mode gain, analog bandwidth, and cross talk. The large number of channels per chip allows a low cost per channel ($\10 to $\20 including front-end and back-end electronics but not including photosensors) to be achieved with a TARGET-based IACT readout system. In addition to basic performance parameters of the TARGET chip itself, we present a camera module prototype as well as a second-generation chip (TARGET~2), both of which have been produced.

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K. Bechtol, S. Funk, A. Okumura, L. Ruckman, A. Simons, H. Tajima, J. Vandenbroucke, G. Varner. 2011-05-10. TARGET: A multi-channel digitizer chip for very-high-energy gamma-ray telescopes. https://doi.org/10.1016/j.astropartphys.2012.05.016

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