[SI-LIST] Re: High-speed serial data transfer

  • From: Hal Murray <hmurray@xxxxxxxxxxxxxxx>
  • To: wangyf@xxxxxxxxxxx
  • Date: Tue, 01 Nov 2005 00:15:30 -0800

> I'm dealing with transfering serial data at the rate of about 500Mbps.
> I want to use cable for electronic signal,  not to use fibre. The
> length of the cable is no longer than 5 meters.This is the trigger
> signal for use in high-energy physic experiments, BER should be less
> than 1E-7. Can any one help me to select technology, cable, and
> connectors? 

Gigabit Ethernet works fine at much longer distances.  I think the details 
are complicated, but you can buy PHY chips that do all the work.

I can't quite figure out what you really want to do.  "trigger" sounds like a 
single pulse where the arrival time is important.  Yet you are asking for 500 
Mbps which has units of bandwidth rather than delay or jitter.  Specifying 
only bandwidth usually means that timing/delay is less important and that 
seems strange if you describe the application as "trigger".


If all you want is a single trigger-pulse, how about just a length of coax?  
Use CMOS or (P)ECL as you prefer.  Go try it in a lab.  Be sure to try 
different types of coax when you have a scope on the receiver.  Big, fat coax 
will generally give you a cleaner signal.

Another approach would be LVDS.  Lots of vendors make LVDS interface chips.  
National's FAQ says:
  * In point-to-point applications the fastest LVDS devices can operate at 
2Gbps.
(It doesn't say how long that link is.  Probably short as in 1/2 meter 
backplane.)

Several vendors make serial/parallel converter chips that are designed to 
take N bits in parallel with a slow clock and send them over a LVDS link.  
The receiving end recovers the clock and gives you back the bits.  They make 
demo boards...

Modern FPGAs support LVDS or similar differential signaling.  If you can get 
the same clock to both ends, you could probably make a good test setup with a 
couple of FPGA demo boards.



-- 
The suespammers.org mail server is located in California.  So are all my
other mailboxes.  Please do not send unsolicited bulk e-mail or unsolicited
commercial e-mail to my suespammers.org address or any of my other addresses.
These are my opinions, not necessarily my employer's.  I hate spam.



------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field

or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list

For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field

List FAQ wiki page is located at:
                http://si-list.org/wiki/wiki.pl?Si-List_FAQ

List technical documents are available at:
                http://www.si-list.org

List archives are viewable at:     
                //www.freelists.org/archives/si-list
or at our remote archives:
                http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
                http://www.qsl.net/wb6tpu
  

Other related posts: