  PARISROC is a complete read out chip, in AMS SiGe 0.35 micron technology [1],
for photomultipliers array. It allows triggerless acquisition for next
generation neutrino experiments and it belongs to an R&D program funded by the
French national agency for research (ANR) called PMm2: Innovative electronics
for photodetectors array used in High Energy Physics and Astroparticles [2]
(ref.ANR-06-BLAN- 0186). The ASIC integrates 16 independent and auto triggered
channels with variable gain and provides charge and time measurement by a
Wilkinson ADC and a 24-bit Counter. The charge measurement should be performed
from 1 up to 300 photo-electrons (p.e.) with a good linearity. The time
measurement allowed to a coarse time with a 24-bit counter at 10 MHz and a fine
time on a 100ns ramp to achieve a resolution of 1 ns. The ASIC sends out only
the relevant data through network cables to the central data storage. This
paper describes the front-end electronics ASIC called PARISROC.
