High-speed Optical Link for Atlas

2.0 Gbps S-LINK LSC and LDC S-LINK Interface

(Circuit number EP680-1169-250)
Link Source Card bottom view (top view).


The HOLA S-LINK interface is a standard S-LINK implementation which uses the TI TLK2501 transceiver both for the forward and for the return channel (one per card). For the optical transmission Small Form Factor Pluggable (SFP) Multimode transceivers with LC Connector are used. As opposed to the ODIN S-LINK, the HOLA can transfer data at the full S-LINK bandwidth of 160 MB/s with only one duplex fiber. Furthermore the HOLA is less expensive than the ODIN.

The design is not intended to be used in an environment with radiation.

General features


The HOLA is a 3.3V only S-LINK card, it can therefore not be used on 5V PMC/PCI interface cards such as the SPS/SSP/SPCIS/SSPCI.


10 October 2001 Hardware specification ready
1 March 2002 Schematics ready and reviewed by Peter Jansweijer/NIKHEF and Tivadar Kiss/CERNTECH.
PCB design will start 7 March
11 April 2002 PCB design finished. 16 boards ordered (5 prototype links and 6 empty PCBs for NIKHEF MDT)
24 April 2002 Empty PCBs will arrive 20 May (delays in ordering because of holidays and miscommunication)
15 May 2002 18 empty PCBs arrived
28 May 2002 6 boards mounted. Found problem with pad stack TLK2501 (IC smaller than pads). No problem for debugging, but needs re-layout for series production.
30 June 2002 One full link debugged and completely working. Aurelio Ruiz, designer of the card, left CERN. Aurelio has won a digital camera with the EBV design contest.
1 July 2002 Jesper Haee will do a full verification and review of the design
11 October 2002 PCB design improved. Review of design finished.
15 January 2003 CERNTECH is producing a first batch of 30 HOLA cards, the modules are expected in February.
November 2003 Due to problems with the supply of the 2.5Gb/s F/O transceivers it was decided to reduce the serial line speed to 2.0Gb/s. This change allows using transceivers designed double speed Fibre Channel applications which are readily available and lower cost as well. The bandwidth of 160MB/s is not affected. The change requires replacing the on-board crystal oscillator with a 100MHz device, existing cards have been modified. HOLA cards delivered by CERNTECH will also be configured for 2.0Gb/s operation.






Aurelio Ruiz  & Erik van der Bij & Stefan Haas - 8 March 2003