Re: [SI-LIST] : Differential End Termination

From: K.Orthner ([email protected])
Date: Sun Feb 25 2001 - 17:10:05 PST

• Next message: selvaraj subramanian : "[SI-LIST] : Termination scheme for SSTL2 Class II"
• Previous message: Lawrence Butcher: "[SI-LIST] : Bypass Cap via placement considered. Negative L's?"
• In reply to: Stockalis, Anthony: "[SI-LIST] : Differential End Termination"
• Next in thread: Mikhail Matusov: "[SI-LIST] : PECL known problem"
• Reply: Mikhail Matusov: "[SI-LIST] : PECL known problem"

Anthony,

OnSemi (formerly Motorola) has a good application note about
differential termination. It explains the different ways it can be done,
and the tradeoffs involved. It focusses primarily on (P)ECL, but the
principles are the same for LVDS and other differential signals.

http://www.onsemi.com/pub/Collateral/and8020rev0.pdf

Also, I've heard many people mention the MECL System Design
Handbook, and it took me a while to find it (searching Motorola's
web site.) . . . This too can be found on the OnSemi web site.

Hope this helps,
-Kent

--
Kent Orthner                         ??  ??
Furukawa Electric                    ??????
5-1-9 Higashi-Yawata, Hiratsuka, 254-0016 Japan
Tel: (0463) 24 8451   Fax:(0463)24-8490
[email protected]
----- Original Message -----
From: "Stockalis, Anthony" <[email protected]>
To: <[email protected]>
Sent: Saturday, February 24, 2001 4:21
Subject: [SI-LIST] : Differential End Termination
> I am investigating the ac end termination of a differential data signal.
I
> have reviewed section 6.4 of Howard Johnson's "Handbook of Black Magic" on
> ac end terminators, and it seems that two resistors to a common capacitor
to
> ground is the way to go.  The recommendation of the chip manufacturer is
to
> have a 50 ohm to .01uF capactor end termination on each line of the
> differential pair.  The chip is a Gigabit Ethernet Chip running at
1.25Ghz.
> This capacitance value seems rather high to me, and I believe that the
> common capacitor would be the correct solution.  I was wondering if anyone
> else has any valuable experience doing ac end terminations on differential
> data lines.  I have used the Mentor Graphics Interconnectix simulator, but
> have not gotten very conclusive results because a random data signal
cannot
> be used in the tool.  Any help would be appreciated.
>
> Thanks,
>
> Anthony Stockalis
> Marconi Communications
> BXR-48000 Hardware Team
> email: [email protected]
> Phone 724-742-6124
>
>
> **** 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
> ****
>
**** 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
****

• Next message: selvaraj subramanian : "[SI-LIST] : Termination scheme for SSTL2 Class II"
• Previous message: Lawrence Butcher: "[SI-LIST] : Bypass Cap via placement considered. Negative L's?"
• In reply to: Stockalis, Anthony: "[SI-LIST] : Differential End Termination"
• Next in thread: Mikhail Matusov: "[SI-LIST] : PECL known problem"
• Reply: Mikhail Matusov: "[SI-LIST] : PECL known problem"

This archive was generated by hypermail 2b29 : Tue May 08 2001 - 14:30:56 PDT