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

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.