General Description; Overview; Fig. 1.1: Data Flow In The Board - Caen V1729 Technical Information Manual

Document type: Title:
User's Manual (MUT) Mod. V1729 4 Channel 12 Bit Sampling ADC

1. General description

1.1

Overview

The CAEN Mod. V1729 board is suited for acquisition of fast analog signals based on the
MATACQ (analog matrix) chip developed by collaboration of the CEA/DAPNIA and the
l'IN2P3/LAL [1].
The V1729 board, in the mechanical format VME double Europe, is compatible with
several standards of acquisition (VME A32/D32, A24/D16, and GPIB).
This board performs the coding of 4 analog channels of bandwidth up to 300MHz over 12
bits at a sampling frequency (Fe) reaching up to 2GHz and over a depth of 2520 usable
points.
This operation is realized in three phases (see Fig 1.1):
Acquisition :
the analog signal is continuously sampled at the frequency Fe in a circular analog
memory. The arrival of a trigger signal initiates the stopping phase of the sampling (2.1.1.
At the end of this phase, the state of the memory is set : it then contains the last 2560
points sampled (of which 2520 are valid).
Numerization and storage :
after a stopping order of the acquisition, the samples stored under analog form in the
MATACQ chips are rapidly (650µs) re-read and coded into digital data over 12 bits, then
stored in a digital memory buffer. The acquisition is informed of the end of the coding
phase either by scrutation of an internal register, or by an interruption.
Reading :
the memory buffer can then be re-read by the acquisition system. For an acquisition
system of VME A24-D16 standard, the latter operation lasts a few ms for the full readout
of a 4-channel board, which permits attaining an acquisition frequency of a few hundred
Hz for the acquisition of 2500 points per channel. With a high performance A32-D32
system, one should reach 1 kHz.
ANALOG
SAMPLING
Input
MATRIX
Fe = 1GS/s or 2GS/s
NPO:
00109/04:V1729.MUTx/03
ADC
5 MHz

Fig. 1.1: data flow in the board

Filename:
V1729_REV3.DOC
Revision date:
22/06/2005
DIGITAL
DIGITAL
MEMORY
BUFFER
PRELIMINARY
Revision:
3
Acquisition
Up to 3MO/s in GPIB
and 20MO/s in VME
Number of pages: Page:
38 5