RE: [SI-LIST] : Non-standard bus termination (2nd posting)

Patterson, Ken (Ken_Patterson@adc.com)
Wed, 22 Sep 1999 08:05:35 -0500

Is it necessary to use an AC termination?? Would another style of termination i.e. series or thevenin style make more sense. I would suggest experimenting or simulating using a series termination. This would limit the number of components. Running a simulation of your net topology with and without termination would give you an idea of where you are at. Whether or not to terminate your bus depends on what kind of overshoot, crosstalk and EMI emissions your system can tolerate.

-----Original Message-----
From: massimo.polignano@esaote.com [mailto:massimo.polignano@esaote.com]
Sent: Wednesday, September 22, 1999 4:45 AM
To: si-list@silab.eng.sun.com
Subject: [SI-LIST] : Non-standard bus termination (2nd posting)

Has anybody out of there any suggestion about the following problem? (I think it
is quite a common one).

I?ve got a board with a non-standard bus of 34 traces. The bus drives a group of
memories.
The lenght of the bus is necessarily higher than the critical lenght (lcr =
tr/2tpd): a termination could be useful. The problem: there are so many traces
that one has to use too many components (34 resistors and 34 capacitors for AC
parallel termination).

What shall I do?
Are there any special components (array) to terminate this type of bus?
Shall I terminate the bus or not? (In past experience not always a termination
was mandatory)

Thanks for any help.

m.p.

---------------------------------------------------------
ESAOTE S.p.A. Massimo Polignano
Research & Product Development Design Quality Control
Via di Caciolle,15 tel:+39.055.4229402
I- 50127 Florence fax:+39.055.4223305
e-mail: massimo.polignano@esaote.com

**** To unsubscribe from si-list: send e-mail to majordomo@silab.eng.sun.com. In the BODY of message put: UNSUBSCRIBE si-list, for more help, put HELP. si-list archives are accessible at http://www.qsl.net/wb6tpu/si-list ****

**** To unsubscribe from si-list: send e-mail to majordomo@silab.eng.sun.com. In the BODY of message put: UNSUBSCRIBE si-list, for more help, put HELP. si-list archives are accessible at http://www.qsl.net/wb6tpu/si-list ****