[SI-LIST] Re: Split gnd planes - for/against? - Thanks!
- From: steve weir <weirsi@xxxxxxxxxx>
- To: "Lakshmi Narayanan Sowrirajan, TLS-Chennai" <lakshminarayanans@xxxxxx>
- Date: Fri, 10 Apr 2009 00:10:21 -0700
http://www.sopworx.com-a.googlepages.com/
Lakshmi Narayanan Sowrirajan, TLS-Chennai wrote:
> Hi Steve,
>
> Where can I download this student version, can you please help
> me on this..?
>
> Thanks & Regards
> Lakshminarayanan.S
> 9840250902
>
> -----Original Message-----
> From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx]
> On Behalf Of steve weir
> Sent: Friday, April 10, 2009 9:23 AM
> To: simsonl@xxxxxxxxxxxxxx
> Cc: Tony Luan; Sol Tatlow; si-list@xxxxxxxxxxxxx
> Subject: [SI-LIST] Re: Split gnd planes - for/against? - Thanks!
>
> Larry, yes it did come with the ChipQuake software. ChipQuake is
> focused on the IC and while it does allow specifying the PCB bypass
> network and package power / ground connections it doesn't not have that
>
> facility. For small problems you could can model in the student version
>
> of Sphinx.
>
> Steve.
> simsonl@xxxxxxxxxxxxxx wrote:
>
>> Steve,
>>
>> The book you mentioned in an earlier post, "Noise Coupling in
>>
> Integrated Circuits", is on amazon.com bundled with a simulation
> software. Did you get yours with that software and can it simulate
> multiple (split) power/ground planes?
>
>> Thanks
>> Larry
>>
>>
>> ---- steve weir <weirsi@xxxxxxxxxx> wrote:
>>
>>
>>> Tony usually that is the right decision. However, there are cases
>>>
> when
>
>>> a package will not fit and still provide adequate isolation between
>>> circuits without implementing a split. These don't happen in digital
>>>
>
>
>>> designs running one signaling level.
>>>
>>> But suppose that you have a big digital bus switching 5A / ns that is
>>>
>
>
>>> 0.25" away from some analog circuit that is sensitive to 10uV noise.
>>>
> Do
>
>>> you think the 0.25" separation will be enough? If you cannot change
>>>
> the
>
>>> placement to put the analog circuitry further away, what will you do?
>>>
>>> Steve.
>>>
>>> Tony Luan wrote:
>>>
>>>
>>>> Hi Sol,
>>>>
>>>> I think to split GND plane is not a good idea.
>>>> For any high frequency noise, GND and power plane are playing
>>>>
> completely
>
>>>> equivalent role. How can a high frequency noise tell which plane is
>>>>
> GND?
>
>>>> Which plane is power? Why not split power plane instead and keep a
>>>>
> solid
>
>>>> complete GND plane, because in package or PCB, we have tons of power
>>>> rails and power islands already.
>>>> The biggest disadvantage to split GND plane I saw is that it
>>>>
> increases
>
>>>> routing difficulty when try to avoid high speed signal, clock,
>>>>
> parallel
>
>>>> bus across those gaps on GND plane.
>>>>
>>>> Thanks
>>>> Tony
>>>> -----Original Message-----
>>>> From: si-list-bounce@xxxxxxxxxxxxx
>>>>
> [mailto:si-list-bounce@xxxxxxxxxxxxx]
>
>>>> On Behalf Of Sol Tatlow
>>>> Sent: Thursday, April 09, 2009 4:58 AM
>>>> To: si-list@xxxxxxxxxxxxx
>>>> Subject: [SI-LIST] Re: Split gnd planes - for/against? - Thanks!
>>>>
>>>> One last mail to put this thread 'to bed'...
>>>>
>>>> Thanks to everyone who took the time to reply, particularly to
>>>> those who actually gave me what I asked for, those reluctant beasts,
>>>> the real-life examples - it's great that you're willing to so fully
>>>> participate in such a discussion. After all, theory is great;
>>>> coupled with real-life examples it's even better.
>>>>
>>>> Of course, the specific examples can't be applied 1:1 to any other
>>>> design, as has been said 'x' times, but I, for one, am nevertheless
>>>> wiser for the experiences that have been shared... I believe I'm a
>>>> good engineer, but won't stop learning 'till the day I die.
>>>>
>>>> It was also good to see that I am not the only one suffering at the
>>>> hands of less-than-perfect datasheets and the implementation of
>>>> often contradictoray 'hints' :) - regardless of simulation results
>>>> and past experiences, it's not always easy when it comes to
>>>> persuading a customer, who is still convinced that app notes are
>>>> written by all-knowing beings, to 'do the right thing'.
>>>>
>>>> Sol
>>>>
>>>>
>>>>
>>>>
>>> --
>>> Steve Weir
>>> Teraspeed Consulting Group LLC
>>> 121 North River Drive
>>> Narragansett, RI 02882
>>>
>>> California office
>>> (866) 675-4630 Business
>>> (707) 780-1951 Fax
>>>
>>> Main office
>>> (401) 284-1827 Business
>>> (401) 284-1840 Fax
>>>
>>> Oregon office
>>> (503) 430-1065 Business
>>> (503) 430-1285 Fax
>>>
>>> http://www.teraspeed.com
>>> This e-mail contains proprietary and confidential intellectual
>>>
> property of Teraspeed Consulting Group LLC
>
> ------------------------------------------------------------------------
> ------------------------------
>
>>> Teraspeed(R) is the registered service mark of Teraspeed Consulting
>>>
> Group LLC
>
>>> ------------------------------------------------------------------
>>> 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 technical documents are available at:
>>> http://www.si-list.net
>>>
>>> List archives are viewable at:
>>> //www.freelists.org/archives/si-list
>>> or at our remote archives:
>>> http://groups.yahoo.com/group/si-list/messages
>>> Old (prior to June 6, 2001) list archives are viewable at:
>>> http://www.qsl.net/wb6tpu
>>>
>>>
>>>
>>>
>>
>>
>
>
>
--
Steve Weir
Teraspeed Consulting Group LLC
121 North River Drive
Narragansett, RI 02882
California office
(866) 675-4630 Business
(707) 780-1951 Fax
Main office
(401) 284-1827 Business
(401) 284-1840 Fax
Oregon office
(503) 430-1065 Business
(503) 430-1285 Fax
http://www.teraspeed.com
This e-mail contains proprietary and confidential intellectual property of
Teraspeed Consulting Group LLC
------------------------------------------------------------------------------------------------------
Teraspeed(R) is the registered service mark of Teraspeed Consulting Group LLC
------------------------------------------------------------------
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 technical documents are available at:
http://www.si-list.net
List archives are viewable at:
//www.freelists.org/archives/si-list
or at our remote archives:
http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
Other related posts:
