This page provides documentation for a simple PCB which provides external inputs and outputs for the trigger and timing signals on the DCOL. The board will be a very simple 6U VME format board which takes only power and GND from the VME bus.

It will have the following front-panel connectors:

  • RJ-45 to/from DCOL module
    • pair (3,6) - LVDS output to DCOL
    • pair (7,8) - LVDS input from DCOL
  • LEMO 1 - NIM fast logic input (drives 3,6 of RJ-45)
  • LEMO 2 - CMOS 3.3V logic output (driven by 7,8 of RJ-45)

The board will need one LVDS transmitter and one LVDS receiver (could be a single transceiver). The NIM fast logic input should be implemented using a fast comparator ("fast" means < 20ns delay) with a threshold set at -400mV. The CMOS logic output should be able to drive 50 ohms to a decent level (>2V). One way to accomplish this is to use a 74ALVC04 hex inverter with three gates in parallel. A perhaps nicer alternative if they still exist is the 74S140 50 ohm line driver.

Please see the ExpressPCB layout on the page below as a starting point. The VME connector, board outline and placement of front panel connectors can be preserved.

Last modified 9 years ago Last modified on Nov 8, 2013, 10:17:53 AM