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Document type:
Title:
Revision date:
Revision:
User's Manual (MUT)
Mod. V791, ICARUS 32-channel analog board
27/05/99
2
NPO:
Filename:
Number of pages:
Page:
00100/98:V791x.MUTx/02
V791MN4.DOC
17
4
1. General description
1.1. Overview
The CAEN Model V791 is a 32-channel analog board designed for optimum performance
as front-end electronics for the ICARUS experiment (see, for example, the web site:
www.aquila.infn.it:80/icarus/
). Its function is to digitize the signals coming from the
detector and transmit them via a fast serial link. The V791 module can adapted to any
detector which uses a charge (or current) preamplifier in Radeka configuration (folded
cascode). For further details about how to adapt the module, please contact the factory
directly.
A functional block of the V791 module is shown in Fig. 2.1. The 32 input signals are sent
to 32 low-noise preamplifiers and relevant shapers. The processed signals are then
multiplexed and digitized in order to be transmitted via the serial link.
The section for the signal digitization consists of four 8-channel blocks. Each block is
made of two 4-channel analog multiplexers and a 20 MHz ADC. Each channel is sampled
at a 2.5 Ms/s rate and digitized with a 10-bit resolution by using a time division
multiplexing technique. The maximum delay between the sampling of a channel and the
following one is 400 ns.
The Model V791 is housed in a 1-unit wide, 6-unit high Eurocard mechanics with special
shielding for the protection of the low-noise circuits.
The module hosts four external connectors:
•
a 64-pin input connector (rear panel),
•
a 30-pin power supply and auxiliary signal connector (rear panel),
•
a serial link connector (front panel),
•
a
Σ
out
connector (front panel).
Please note that, although the module is housed in a Eurocard standard mechanics, the
rear connectors are not VME standard connectors since the backplane for which the
board has been designed is proprietary.
Two different version are available, specifically the Mod. V791C and the Mod. V791Q
which, respectively, allow for the digitalisation of the input current and the digitalisation of
the input charge. These two version differ only for the values of the components mounted
near the preamplifiers and the shapers. The main technical specifications of both
versions are reported in Table 1.1.
