[SI-LIST] : Z Odd-mode, edge-coupled, 50ohms?

About this list Date view Thread view Subject view Author view

From: [email protected]
Date: Mon Jan 15 2001 - 14:13:12 PST

Hi all,

I'm in a little need here. I'm a PCB layout person doing a design where
the engineer would like his "pairs" (positive/negative mode) run to give
him 50ohms, edge-coupled, Z-odd mode (what?) coupling which terminate
thorugh 100ohm resistors. What? If someone could put this in more
layman's terms for me I'd really appreciate it. I look at the spec he's
supposedly using and it shows the driver driving the pos/neg signals
thru caps (AC), or not (DC) and with 50 ohm traces to the 100ohm
resistors at the load pins. I've typically done this, but I've never
heard such terminology before.

I'm used to routing 50ohm lines with proper spacings for the pairs as
well as staying "comfortably" away from other pairs or other traces. Is
this really what he's after or am I missing something.

He had first mentioned he wanted the pairs routed as either edge-coupled
100ohm differential or broadside coupled differentials, but when I
questioned him on it he changed the tune.

When is 100ohm differential routing required? Is there some indication
in the device (chip) specs that points to it?


Tired of limited space on Yahoo and Hotmail?
Free 100 Meg email account available at http://www.dacafe.com

**** To unsubscribe from si-list or si-list-digest: send e-mail to
[email protected] In the BODY of message put: UNSUBSCRIBE
si-list or UNSUBSCRIBE si-list-digest, for more help, put HELP.
si-list archives are accessible at http://www.qsl.net/wb6tpu

About this list Date view Thread view Subject view Author view

This archive was generated by hypermail 2b29 : Tue May 08 2001 - 14:30:37 PDT