  The Cherenkov Telescope Array (CTA) will be the next generation ground-based
gamma-ray observatory. CTA consists of different telescope types of which the
largest ones (Large-Sized Telescopes, LSTs) cover the lower energy range,
between 20 GeV and 200 GeV. The first LST is currently being commissioned at
the Roque de los Muchachos Observatory, La Palma, Canary Islands. Its camera
has 1855 photomultipliers (PMTs) with 1.5 inch cathodes. Silicon
Photomultipliers (SiPMs) are increasingly becoming valid alternatives to PMTs
also in gamma-ray astronomy. In the context of the LST project, there is an
effort to study a novel Advanced Camera, equipped with SiPMs and a completely
redesigned electronics based on a fully digital approach. To study and develop
solutions on the sensors of these camera, we built a prototype camera module
with a fully re-designed pre-amplifying stage and sensor bias control while
re-using the digitizing and triggering stages of the existing LST camera
module. We report on the design choices made to achieve the highest performance
in terms of timing and charge resolution and the laboratory measurements
validating those choices.
