Re: [SI-LIST] : crosstalk through resistor networks?

Joe Cahill (jjcahill@us.ibm.com)
Fri, 14 Aug 1998 14:14:21 -0400

Watch out for L*di/dt noise across any common power or ground pins in the
resistor package. In parallel terminators switching current in one resistor can
disturb the supply or ground to the other resistors, and drag around the net
connected to the other resistors. Probably not a problem, but worth a few
minutes to estimate.

Joe

CEC Analysis and I/O Design
Phone: 507.253.0762 Fax: 507.253.4966
jjcahill@us.ibm.com

owner-si-list@silab.Eng.Sun.COM on 08/14/98 08:36:55 AM
Please respond to andrew@scs.ch
To: si-list@silab.Eng.Sun.COM
cc:
Subject: [SI-LIST] : crosstalk through resistor networks?

Hello,

I am interested in using some small-package (QSOP) resistor networks for
terminating a large number of bus-signals in a design. Signal rise-times
range from ~200ps to 1ns or so.

I have found some devices that look suitable here:
http://www.bourns.com/cat/MNETXX1.htm

I am wondering whether such an approach will have crosstalk problems.
Has anyone analysed this and can give me some advice?

I presume that if traces are suitably separated before and after the
resistor package then the crosstalk induced between adjacent signals
will be reduced. These signals are very close together for the 3mm or so
across the resistor package - is this likely to cause problems?

Thanks for any help,

Andrew Phillips
Supercomputing Systems AG
Zurich, Switzerland

Need 'C6x DSP info?
http://www.scs.ch/~andrew/c6x.html
*

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