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Re: gEDA-user: pcb, howto partition power planes?
Were you trying to format them with HTML?
I bet the HTML filters on the mailing list were cutting out the links.
On Oct 30, 2008, at 2:44 PM, Eric Winsor wrote:
> Steve,
>
> I don't see these other attempts.
>
> Eric Winsor
>
> Steve Meier wrote:
>> Dave,
>>
>> No I struggled three times to get usable url's so go down a couple
>> more
>> of my attempts and then you will have to take the line breaks out
>> of the
>> ultra long url but you can get there.
>>
>> Steve Meier
>>
>>
>> On Thu, 2008-10-30 at 16:29 -0400, Dave McGuire wrote:
>>
>>> I don't see any URLs in there..
>>>
>>> -Dave
>>>
>>> On Oct 29, 2008, at 6:08 PM, Steve Meier wrote:
>>>
>>>> I went looking to see if the Analog Device book was available
>>>> electronically. Here are the links.
>>>>
>>>>
>>>> Steve Meier
>>>>
>>>>
>>>> High Speed System Applications Table of Contents
>>>>
>>>>
>>>>
>>>> High Speed System Applications Section 1: High Speed Data
>>>> Conversion
>>>> Overview
>>>>
>>>>
>>>>
>>>> High Speed System Applications Section 2: Optimizing Data Converter
>>>> Interfaces
>>>>
>>>>
>>>>
>>>> High Speed System Applications Section 3: DAC, DDS, PLL's, and
>>>> Clock
>>>> Distribution
>>>>
>>>>
>>>>
>>>>
>>>> High Speed System Applications Section 4: PC Board Layout and
>>>> Design
>>>> Tools
>>>>
>>>>
>>>>
>>>> On Tue, 2008-10-28 at 13:44 -0700, Steve Meier wrote:
>>>>
>>>>> I won't argue this point. I will refer every one to an Analog
>>>>> Device
>>>>> publication "High Speed System Applications" copyright 2006
>>>>> ISBN-10:
>>>>> 1-56619-909-3 or ISBN-13: 978-1-56619-909-4
>>>>>
>>>>> In particular if you get a copy of this book (and they gave me
>>>>> mine)
>>>>> look at pages 4.15 and 4.16
>>>>>
>>>>> There AD recommends connecting both of the A/D grounds "digital"
>>>>> and
>>>>> "analog" to the analog ground plane "this is because it causes
>>>>> less
>>>>> problems for the relatively small amount of digital return current
>>>>> to be
>>>>> returned through the analog ground than it would to connect the
>>>>> converter to the much noisy digital ground.
>>>>>
>>>>> There is a lot more talked about then just that one blurb.
>>>>>
>>>>> Steve Meier
>>>>>
>>>>>
>>>>>
>>>>> On Tue, 2008-10-28 at 11:22 -0700, Joerg wrote:
>>>>>
>>>>>> Stefan Salewski wrote:
>>>>>>
>>>>>>> Sometimes it is necessary/recommended to partition (separate)
>>>>>>> power or
>>>>>>> ground planes, i.e. for ADC or DC/DC-Converters, see page 16 and
>>>>>>> 17 in
>>>>>>>
>>>>>>> http://focus.ti.com/lit/ug/slwu028c/slwu028c.pdf
>>>>>>>
>>>>>>> We can do this in pcb program with (adjoining) polygons.
>>>>>>> Disadvantage is, that if we change the size of one of the
>>>>>>> polygons we
>>>>>>> have to manually adjust the other sizes. A other method may be
>>>>>>> so divide
>>>>>>> a large polygon by copper clearing traces (with trace width
>>>>>>> zero).
>>>>>>>
>>>>>>> This is related to my question from
>>>>>>>
>>>>>>> http://archives.seul.org/geda/user/Sep-2008/msg00387.html
>>>>>>>
>>>>>>> but not identical.
>>>>>>>
>>>>>>> What is the best way to handle this?
>>>>>>>
>>>>>>>
>>>>>> I can't speak to that but just one word of caution: In my 20+
>>>>>> years in
>>>>>> engineering I have yet to see one case where splitting a ground
>>>>>> plane
>>>>>> under high-speed ADCs has worked. Regardless of what application
>>>>>> notes
>>>>>> say. Usually it didn't work, lots of noise. Or it kind of
>>>>>> worked but
>>>>>> fell apart the instant somebody whipped out a GSM cell phone or
>>>>>> BlackBerry.
>>>>>>
>>>>>> Myself, I never spilt a ground place. OTOH the industry
>>>>>> practice of
>>>>>> splitting planes is providing part of my income :-)
>>>>>>
>>>>>> The only time I split is where required for safety, for example
>>>>>> patient
>>>>>> isolation per 60601 (ECG, ultrasound etc.).
>>>>>>
>>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> geda-user mailing list
>>>>> geda-user@xxxxxxxxxxxxxx
>>>>> http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
>>>>>
>>>>
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>>>>
>>>
>>
>>
>>
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>
>
>
>
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