Re: [SI-LIST] : Clock and Transmission Line Termination

Dennis Tomlinson ([email protected])
Tue, 12 May 1998 10:18:16 -0500

Eric B. Lewis wrote:

> Does anyone know were I can get any general back ground information on the
> termination of Transmission and or clock lines on a PCB, such as selection
> of termination resistor values.
> Eric B. Lewis
> VoiceMail:972.575.7798
> Pager:972.598.3852
> Raytheon TI Systems
> 6600 Chase Oaks Blvd.
> Plano, Texas 75023

Hi Eric,

There are any number of good App. notes to be found on the web pages of
companies like National Semi, Motorola, TI, IDT, etc.

Some good text can be found in: "High Speed Digital Design ..." by Johnson
and Graham; and "BiCMOS / CMOS Systems Design" by Buchanan. The
latter has been updated in the last few years, though I haven't seen it yet.

My personal favorite remains "MECL System Design Handbook" by Motorola.
My copy, dated 1988, has yellowing, dog eared pages with annotated margins.
I don't know whether or not this "Handbook" is still in print.

Even when armed with all this theoretical information, my experience has been

that termination strategies, routing topologies, and device technologies are
inseparably intertwined, that access to a good SI simulator is a must.
I have used QUAD Design's PreVue, Mentor Graphics' ICX "Sandbox", and
Hyperlynx LINESIM. With good device and transmission line models, reasonable
predictive results can be had.