Optical Link

1
Optical Link

• Transmitter board to be plugged on the ROB
• 8 Bit at 120 MHz DDR parallel to 16 bit SDR 125
  MHz conversion using CPLD
• Commercial gigabit serializer from Texas
  Instruments TLK2501
• Driver for the laser diode with programmable
  parameters via I2C interface
• Simplified I2C slave in CPLD for the
  configuration of the TLK2501 and for control
  counters
• Receiver board for testing of the gigabit
  transmitter board
• Amplifier for the photodiode
• The same commercial gigabit deserializer from
  Texas Instruments

2
Optical Link Test Setup
Logic Analyzer
TRAP
NI
PC
Opt. Cable
I2C/JTAG
3
Optical Link Test Results
Stable operation at 2.5 GBits/s with pseudorandom
data generated in the TI chip Thousands of data
packets send from one TRAP chip over the serial
link No transmission errors in the serial
link Real length of the optical cable with the
path panel interconnections, 850 nm Still some
rare (in 0.2 of the data words) single bit
errors in only one bit, possible reasons are
clock quality or timing problems between the CPLD
and the TLK2501.
4
OASE
Operation at 2.5 Gbits/s with pseudorandom
data Test setup using TRAP chip for sending
data Real length of the optical cable with the
patch panel interconnections, 850 nm SFP FPGA
as data receiver and checker
5
GTU Track Matching Unit (TMU)

• PCB simulations
• Impedance matching
• Crosstalk
• Submission on 28.11.05

850 nm SFP-Transceiver
Custom LVDS I/O72 Pairs
850 nm SFP-Transceiver
850 nm SFP-Transceiver
DDR2 SDRAM
128 MB
850 nm SFP-Transceiver
JTAG
850 nm SFP-Transceiver
FPGA (Xilinx XC4VFX40 FF1152)
DDR2 SRAM
850 nm SFP-Transceiver
4 MB
850 nm SFP-Transceiver
850 nm SFP-Transceiver
Config PROM
850 nm SFP-Transceiver
850 nm SFP-Transceiver
CompactPCI Bus
850 nm SFP-Transceiver
850 nm SFP-Transceiver
(6U Height, Single Width)