Sie befinden Sich nicht im Netzwerk der Universität Paderborn. Der Zugriff auf elektronische Ressourcen ist gegebenenfalls nur via VPN oder Shibboleth (DFN-AAI) möglich. mehr Informationen...
Journal of instrumentation, 2022-07, Vol.17 (7), p.P07006
Ort / Verlag
Bristol: IOP Publishing
Erscheinungsjahr
2022
Quelle
Alma/SFX Local Collection
Beschreibungen/Notizen
Abstract
A characterisation of the Timepix4 pixel front-end with a
strong focus on timing performance is presented. Externally
generated test pulses were used to probe the per-pixel
time-to-digital converter (TDC) and measure the time-bin sizes by
precisely controlling the test-pulse arrival time in steps of
10 ps. The results indicate that the TDC can achieve a time
resolution of 60 ps, provided that a calibration is performed to
compensate for frequency variation in the voltage controlled
oscillators of the pixel TDCs. The internal clock distribution
system of Timepix4 was used to control the arrival time of
internally generated analog test pulses in steps of about
20 ps. The analog test pulse mechanism injects a controlled amount
of charge directly into the analog front-end (AFE) of the pixel, and
was used to measure the time resolution as a function of signal
charge, independently of the TDC. It was shown that for the default
configuration, the AFE time resolution in the hole-collecting mode
is limited to 105 ps. However, this can be improved up to about
60 ps by increasing the preamplifier bias-current at the cost of
increased power dissipation. For the electron-collecting mode, an
AFE time resolution of 47 ps was measured for a bare Timepix4
device at a signal charge of 21 ke. It was observed that additional
input capacitance from a bonded sensor reduces this figure to
62 ps.