VX1743

The Mod. VX1743 is a VME64X 6U module housing 16 Channel 12 bit 3.2 GS/s Switched Capacitor Digitizer, with 2.5 Vpp single-ended input dynamics, issued from the collaboration with CEA/IRFU & CNRS/IN2P3/LAL and based on SAMLONG chip. A programmable DAC on each channel allows for DC Offset adjustment in the ±1.25 V range.

The analog input signals are continuously sampled into the SAMLONGs (sampling intervals down to 312.5 ps) in a circular analog memory buffer (1024 cells). As a trigger signal arrives, all analog memory buffers are frozen and subsequently digitized with a resolution of 12 bits into a digital memory buffer. During analog to digital conversion process, the VX1743 cannot handle other triggers (Dead Time: 115 us).

The memory buffer allows to store up to 7 full events for each cannel (1 event = 1024x12bit). The buffer can be read by VME bus or Optical Link simultaneously with write operation of successive events.

The module features front panel Clock Input and Output, as well as a PLL for clock synthesis from internal/external references. VX1743 supports multi-board synchronization allowing all switched capacitor memories to be synchronized to a common clock source and ensuring Trigger time stamps alignment. Once synchronized, all data will be aligned and coherent across multiple VX1743 boards.

Each channel is equipped with an individual discriminator, with programmable threshold, which generates a trigger request when the input signal goes over threshold. The trigger requests from the channels are processed by the board to generate a common trigger causing all the channels to acquire an event simultaneously. The common trigger can also be provided externally via the front panel Trigger Input or via the software, for debug purposes, through VMEbus/Optical Link.

VX1743 houses VME (VME64X compliant) and Optical Link interfaces. The VME interface allows data transfers of 60 MB/s (MBLT64), 100 MB/s (2eVME), 160 MB/s (2eSST). The Optical Link supports transfer rate of 80 MB/s and offers Daisy chain capability. Therefore, it is possible to connect up to 8/32 ADC modules to a single Optical Link controller (Mod. A5818).

Mod. VX1743 features an embedded Charge Mode, where the pulse integration window is defined by the user (high rates ~3.5 KEvents/s). This feature allows to perform on-line processing on detector signal directly digitized.

Some typical applications:

• Precise characterization of high speed detectors (PMTs, SiPMs, APDs,…)

• High Resolution Photon timing with MCP-PMTs

Software available (Windows and Linux):
CAEN provides drivers for all the different types of physical communication channels, a set of C libraries (CAENComm and CAENDigitizer) for Windows and Linux OS, as well as a control software tool for Windows:

• CAENUpgrader: tool that allows the user to update the firmware of the digitizers, change the PLL settings, load, when requested, the license for the pay firmware and other utilities.

• WaveCatcher: fully graphical program that implements an oscilloscope.

×Note: VX1743 can be operated with VME8004B / VME8004X / VME8008B / VME8008X / VME8010 / VME8011 / VME8100 / VME8200.
Never use this digitizer with crates VME8001, VME8002, VME8004 and VME8004A. Overheat may damage the module.

The VX1743 fits in the single-slot CAEN VME64X u-crate, which allows you to convert the VME digitizer into a desktop board for lab tests.