[sdiy] Ground planes

[Magnus Danielson]

cheater cheater wrote:
> On Wed, Mar 31, 2010 at 23:21, Magnus Danielson
> <magnus at rubidium.dyndns.org> wrote:
>   
>> Ingo Debus wrote:
>>     
>>> Am 31.03.2010 um 01:55 schrieb Magnus Danielson:
>>>
>>>       
>>>>  it just isn't used in the audio-realm since the need for ground-planes
>>>> is almost none.
>>>>         
>>> But aren't HF properties important even in very low frequency circuits
>>> when it comes to EMC?
>>>       
>> Well... most of them can be handled fairly well locally where needed. We
>> rarely use fast parts, so doing the 100 nF ceramic cap between the power
>> pins on digital and comparators and keeping those leads short should get
>> most of it. It's not like you want to support a few hundred MHz or so on a
>> regular basis. It's when the more fun processor stuff occurs that some more
>> attention is needed.
>>
>> So, for most part doing it for HF-reasons seems a bit of an over-kill. Doing
>> it to save etching seems much more reasonable to me at least. If someone can
>> show me a case where it has or should have impact,
>>     
>
> Your synth is standing next to your computer, TV, network switch, fan,
> or some other source of HF EMI.
Not really, but regardless, groundplanes in themselves is not very 
effective measure. It would take a bit more effort to handle that EMI 
properly if you cared. That aspect would require some thought to treat 
the places which really is affected by RF radiation.

Cheers,
Magnus - been doing a bit of EMC and signal integrity work