[SI-LIST] LVPECL termination and offset crossing
- From: bala <balaseven@xxxxxxxxx>
- To: "si-list@xxxxxxxxxxxxx" <si-list@xxxxxxxxxxxxx>
- Date: Wed, 16 Oct 2013 19:29:59 +0530
Hi all,
I have some questions on the LVPECL termination techniques.DC path to
ground is needed to enable my output transistor irrespective of my receiver
logic. So I am adding 150ohm resistor to ground at driver side .Every
vendor suggest different termination scheme for receiver side, some vendor
recommend thevenin termination and some vendor suggest 50 ohm to Vcc-2.I
understand that to avoid the addition of new voltage scheme for Vcc-2,we
are using thevenin termination scheme. Some vendors suggest 100 ohm
parallel termination. I did simulate 156Mhz differential LEPECL which has
unbalanced differential choke on each signal, with two different
termination scheme, one with 100ohm, another one with thevenin termination
.Differential results looks good for both cases, whereas ,my single ended
waveform shows crossing offset when I use 100ohm termination. I did the
simulation again with thevein termination and crossings are reasonable. Why
we are getting offset crossing while using 100ohm termination?
--
bala
------------------------------------------------------------------
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 forum is accessible at:
http://tech.groups.yahoo.com/group/si-list
List archives are viewable at:
//www.freelists.org/archives/si-list
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
Other related posts:
