[SI-LIST] Re: Single-point grounding and multi-point grounding

  • From: steve weir <weirsi@xxxxxxxxxx>
  • To: si-list@xxxxxxxxxxxxx
  • Date: Fri, 28 Dec 2012 11:43:50 -0800

Rules of thumb can be very dangerous things.

Steve.
On 12/28/2012 10:40 AM, Lynne C. Green wrote:
> I seem to remember another rule of thumb about keeping digital and
> analog grounds separate all the way to the edge of the PCB.  Ditto power
> if possible.
>
> - Lynne
>
>
> On 12/28/2012 2:15 AM, Elya B. Joffe wrote:
>> Dear all,
>> I would suggest that the "frequency" above which to use Multi-Point
>> grounding should be determined not only by "clock rate" (i.e., PRF) but
>> primarily, by edge rate. Since edge rates all today mostly in the
>> sub-nanosecond, I would suggest that for digital circuits, multi-point
>> would probably be the best strategy.
>>
>> In case of doubt, I use a single "hard" connection and multiple
>> capacitive-coupled ground connections (frequency-selective grounds).
>> This would offer multi-point connection at higher  frequencies and
>> single point at lower frequency.
>>
>> Happy New Year,
>>
>> Elya
>>
>> On 28/12/2012 10:53, Tesla wrote:
>>> Hi,
>>>     
>>> Happy holiday.
>>> Read a app note written by Intel--Intel IXP42 product line of network 
>>> processor and IXC1100 control plane processor. For the grounding issue,Page 
>>> 65, it use follow guideline:
>>>     
>>> Use single-point grounding for low-frequency applications (audio, etc.) 
>>> with clock rates of 1MHz or lower.
>>> Use multi-point grounding for high-frequency circuits with clock rates of 
>>> 1MHz or higher.
>>> I know single-point is a tech used when in these days multi-layer PCB is 
>>> not popular. For two layer PCB,it is a good design thumb rule.
>>> Do we still need use single-point grounding for low frequency audio signal 
>>> with complete ground plane PCB in today?
>>>     
>>> Regards.
>>>     
>>> Tesla.
>>>
>>> ------------------------------------------------------------------
>>> To unsubscribe from si-list:
>>> si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
>>>
>>> or to administer your membership from a web page, go to:
>>> //www.freelists.org/webpage/si-list
>>>
>>> For help:
>>> si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
>>>
>>>
>>> List forum  is accessible at:
>>>                   http://tech.groups.yahoo.com/group/si-list
>>>
>>> List archives are viewable at:
>>>             //www.freelists.org/archives/si-list
>>>     
>>> Old (prior to June 6, 2001) list archives are viewable at:
>>>                     http://www.qsl.net/wb6tpu
>>>      
>>>
>>>
> ------------------------------------------------------------------
> To unsubscribe from si-list:
> si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
>
> or to administer your membership from a web page, go to:
> //www.freelists.org/webpage/si-list
>
> For help:
> si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
>
>
> List forum  is accessible at:
>                 http://tech.groups.yahoo.com/group/si-list
>
> List archives are viewable at:
>               //www.freelists.org/archives/si-list
>   
> Old (prior to June 6, 2001) list archives are viewable at:
>               http://www.qsl.net/wb6tpu
>    
>
>


-- 
Steve Weir
IPBLOX, LLC
150 N. Center St. #211
Reno, NV  89501
www.ipblox.com

(775) 299-4236 Business
(866) 675-4630 Toll-free
(707) 780-1951 Fax

All contents Copyright (c)2012 IPBLOX, LLC.  All Rights Reserved.
This e-mail may contain confidential material.
If you are not the intended recipient, please destroy all records
and notify the sender.

------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field

or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list

For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field


List forum  is accessible at:
               http://tech.groups.yahoo.com/group/si-list

List archives are viewable at:     
                //www.freelists.org/archives/si-list
 
Old (prior to June 6, 2001) list archives are viewable at:
                http://www.qsl.net/wb6tpu
  

Other related posts: