  In many physical experiments and applications with photomultiplier tubes
(PMTs), high-speed pulse digitalization is used extensively. The current pulse
from a PMT has a rising time of several to a hundred nanoseconds. The current
pulse shape can be used to obtain the pulse energy and discriminate between
different particles. The conventional readout system with a PMT uses the
discrete or integrated pulse-shaping circuits and analogue-to-digital converter
boards which are based on the NIM or VME system to implement the data
acquisition function. In many applications, such as security instruments, there
are only several PMTs used in the whole system, or in some distributed
applications, long-distance analogue cable with high-voltage power cable is not
applicable due to the tremendous number of channels and enormous distributed
space. In this paper, an integrated digitizer base is designed and interfaced
with a Cs2LiYCl6 (CLYC) scintillator with a PMT. The CLYC scintillator has the
ability to realize the pulse shape discrimination (PSD) between the neutron and
gamma-rays. There is only one Gigabit of unscreened twisted-pair cable needed
for over 700 Mbps TCP data throughput and more than 10 W power. The boards of
high voltage supply, current sensitive preamplifier, 500 MSPS/12-Bit ADC
(Analog-to-Digital Converter), readout module based on ZYNQ SoC (System on
Chip), power over Ethernet, and user interface circuits are stacked with
board-to-board connectors. The system can achieve 4.6% gamma-ray energy
resolution at 662 keV with a 20-{\mu}s pulse integral and PSD figure-of-merit
of ~3.0 for the whole energy of neutrons and gamma-rays. This integrated
digitizer base can also be interfaced with other detectors with a PMT.
