Introduction:
The Optoboard System is the data aggregation and signal conversion stage of the ATLAS ITk Pixel data transmission chain. The basic working principle is:
- DATA: 6x 1.28 Gbps electrical links from the front-end modules are serialized into 1x 10.24 Gbps optical link and transmitted to the backend (FELIX).
- CMD: 1x 2.56 Gbps optical link with trigger and command are deserialized into 8x 160 Mbps electrical links and transmitted to the front-end (ITkPix). Also the Optoboard gets controlled through the optical link.
One Optoboard consists of:
- 4 lpGBTv1: one as a master available through IC, three as slaves controlled through I2C controller of the master. Manual/description here.
- 4 GBCR2: all controlled through lpGBT master I2C controller. Manual here.
- 1 VTRx+: controlled through lpGBT master I2C controller. Description here.
- 1 bPOL2V5 carrier board: houses the bPOL2V5 ASIC that converts 2.5 V to 1.2V. Datasheets here.
Specific for SLAC's test-Optopanel will be marked in red.
Mechanics:
- Up to 8x Optoboards are housed in one Optobox. One Optobox consists also of:
- 1 Powerboard: hosts 5 bPOL12V ASICs (conversion 9 V to 2.5 V) and 1 MOPS chip
- 1 Connectorboard: handles power distribution form the 5 bPOL12V to the 8 Optoboards according the SP chain powering/detector layout.
- Up to 28x Optoboxes (14x normal, 14x mirrored) are housed in one Optopanel.
- Each side of the ITk has 4 Optopanels.
Currently specific for SLAC IS demonstrator:
4x Optoboards are housed in one Optobox. This Optobox is housed in a Test-Optopanel.
Interfaces:
Please refer to our Interface Document here. All the connectors of the Optoboard System is explained there.
Schematics:
All schematics for all of Berns designed PCBs can be found here.
Optoboard sytem support:
We collect support requests and general questions on our Mattermost channel Bern-Optoboard (invite link).
Optoboard software for FELIX:
We created a repository with scripting software to easily configure the Optoboard: https://gitlab.cern.ch/bat/optoboard_felix. A lot is documented in the readme and wiki of the repository.
In a currently ongoing effort by Bern PhD student Daniele dal Santo, the software will be integrated into the ITk demonstrator software itk-demo-sw.
Test-Optopanel at SLAC:
The test-Optopanel houses one Optobox with 4 Optoboards. It has a twinax inlet (round) and a fibre outlet (rectangle). The Optobox is mounted on a cooling plate with two 8 mm pipes. The
A collection of photographs from the test-Optopanel and its sister at CERN SR1 can be found here. See also this Twiki here of the SR1 test-Optopanel which has similiar information (but some very different configurations).
Optoboards:
slot: | OB1 | OB2 | OB3 | OB4 | OB5 | OB6 | OB7 | OB8 |
---|---|---|---|---|---|---|---|---|
serial: | 2400006 | - | 2400003 | - | 2400007 | - | 2400013 | - |
powering from bPOL: | A | A | B | B | C | C | D | D |
FELIX link: |
Connectors:
Check the above interfaces document for more detailled description.
Banana plugs are labelled according to powered bPOL12V.
Cooling and dry air inlet/outlet: FESTO 8 mm
DCS:
Currently no MOPS is mounted on the Powerboard inside the test-Optopanel (due to availability). We will ship one as soon as we got our hands on them.