  One of the main goals of the Cherenkov Telescope Array (CTA) observatory is
to improve the $\gamma$-ray detection sensitivity by an order of magnitude,
compared to the current ground-based observatories. Widening the energy
coverage down to 20 GeV and up to 300 TeV is also an important goal. This goal
will be possible by using Large-Sized Telescopes (LSTs) for the energy range of
20--200 GeV, Medium-Sized Telescopes (MSTs) for 100 GeV--10 TeV, and
Small-Sized Telescopes (SSTs) for energies above 5 TeV. The LSTs, which focus
on the lowest energies, are operated in a region dominated by background events
originated from the night sky background. To reduce such background events as
much as possible, the LST cameras are only read out if at least two of them
have been triggered in a short-time coincidence window. Such trigger is
implemented for each LST camera in a dedicated module called Trigger Interface
Board (TIB). In addition, the TIB is also used in MSTs equipped with the
NectarCAM camera system to manage the different trigger and timing signals
between LSTs and MSTs, as well as to monitor the different counting rates and
dead-time of the cameras. It also assigns a time stamp to each event, which is
recorded along with the information provided by the CTA global timing
distribution system, based on the White Rabbit protocol. Therefore, the event
arrival time can be determined in a redundant way. In this contribution, the
main features and the technical performance of the TIB are presented.
