JESD204B over fiber - Page 1
Forum section: electronics / general

author: schildch
author_rank: Newbie
timestamp: January 31, 2023, 01:25:00 pm
content: Hello everyone,I have a project, were I have a high speed ADC with a JESD204B interface in a remote location (tens of meters away). I am currently considering connecting the ADC to the main processing platform over an optical fiber. Does anybody have some experience with the reliability/stability of JESD204B over fiber? Or any general tips e.g. selection of transceiver, clocking, …?

author: fourtytwo42
author_rank: Super Contributor
timestamp: January 31, 2023, 04:39:13 pm
content: 2 second search getshttps://www.ti.com/lit/an/slyt663/slyt663.pdfand there are plenty more.

author: ejeffrey
author_rank: Super Contributor
timestamp: January 31, 2023, 08:39:12 pm
content: #1 question is do you need determenistic latency/phase alignment of multiple ADCs needed? If so you need to use subclass 1 w/ SYSREF. If not and subclass 0 is sufficient then it should be easy: you basically just wire it up and go. The application note linked above talks about how to distribute clock and SYSREF in a multi-converter setup.What are your sample rate / bit depth / channel count needs? JESD204b is limited to 12.5 Gb/s with a 10 Gb/s effective data rate from 8b10b encoding. Depending on your needs you might at least look for a JESD204c converter that can operate at a higher data rate, allowing you to get by with fewer lanes (and fewer fibers). ~28 Gb/s optical modules are fairly common since they are used for 25/100 Gb/s ethernet.

author: tchiwam
author_rank: Regular Contributor
timestamp: February 01, 2023, 01:41:30 pm
content: I am getting a kit of SFP+ today for similar purpose. My plan is to bring the clk and pps back to the sender to 0 skew the remote clk distribution.For me it is to keep the time reference on a solid platform while the receivers are going to move around.

author: glenenglish
author_rank: Frequent Contributor
timestamp: March 01, 2023, 11:02:26 pm
content: I have done thisI sent clock out to the ADC board, and used a PLL out there to clean up the jitter of the link clock.because we all know clean clocks are the secret to sampling happiness.I also sent sync control on fibre (clocked by the source clock) , and also the SPI control of the converters - I multiplexed them onto one strand and used a small FPGA at the ADC end to demux the signals.-glen

author: chaloz
author_rank: Newbie
timestamp: September 30, 2024, 11:24:32 am
content: Hi Guys,I am working with Ireland's Metrology Laboratory and it would be extremely useful for us to have a way of transferring 1PPS and 10MHz clock signals over optical cable.I was wandering if you'd be open to share your design @glenenglish, or @ tchiwam you mentioned in your posts for 1PPS and 10MHz transmission over optical fibre for high accuracy/stability signals as used by metrology laboratories.Please let me know.Thank you and best regardsZdenek

author: glenenglish
author_rank: Frequent Contributor
timestamp: October 03, 2024, 07:31:37 am
content: just hook up a driver to the laser diode...

author: yifeng.yuan
author_rank: Newbie
timestamp: November 22, 2024, 04:07:24 pm
content: Has anyone tried JESD204C and JESD204D over optical fiber?

author: yifeng.yuan
author_rank: Newbie
timestamp: November 25, 2024, 06:55:21 pm
content: CFBR - I make another post for JESD204C over fiber specifically:https://www.eevblog.com/forum/fpga/jesd204c-over-optical-fiber/msg5723267/#msg5723267