[SI-LIST] Reflection on differential termination
- From: shekhar sharma <sinnovate88@xxxxxxxxxxx>
- To: si-list@xxxxxxxxxxxxx
- Date: Thu, 17 Aug 2006 11:42:55 +0100 (BST)
Hello all,
I have a differential driver terminated by 100-ohm at the far
end. This is a differential termination between two lines A and B. Termination
resistance is matching with the differential characteristic impedance of the
trance.
Initially signal value on A is 300mV and signal value on B is 600mV. This
time common mode voltage is 450mV. Now A is rising from 300mV to 600mV with
rise time of 1ns. B falls from 600mV to 300mV with 1ns fall time but skew
between A and B is 500ps, means B starts falling 500ps after A starts rising.
For the 500ps time A reaches from 300mV to 450mV. During this period there will
be change in common mode values of 150mV.
I have seen observed that this 150mV rise of A (B remains constant), will
cause 75mV reflection on A and 75mV rising of signal at B. I am not able to
explain this effect that why the half of delta Vos (change in common mode) is
going to B and half is reflected back to the source on trace A.
Thanks in advance,
Sekhar
---------------------------------
Here's a new way to find what you're looking for - Yahoo! Answers
Send FREE SMS to your friend's mobile from Yahoo! Messenger Version 8. Get it
NOW
------------------------------------------------------------------
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:
