[Arm-netbook] HDMI High-Frequency Layout: Recommendations--Taper

[Luke Kenneth Casson Leighton]

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crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68


On Mon, Dec 18, 2017 at 2:55 PM, Richard Wilbur
<richard.wilbur at gmail.com> wrote:
> On Mon, Dec 18, 2017 at 3:02 AM, Luke Kenneth Casson Leighton
> <lkcl at lkcl.net> wrote:
>> On Mon, Dec 18, 2017 at 7:02 AM, Richard Wilbur
>> <richard.wilbur at gmail.com> wrote:
>>> On Sun, Dec 17, 2017 at 11:34 PM, Luke Kenneth Casson Leighton
>>> <lkcl at lkcl.net> wrote:
>>>> On Mon, Dec 18, 2017 at 6:31 AM, Richard Wilbur
>>>> <richard.wilbur at gmail.com> wrote:
>>>>> 1.  Ground keepout under whole ESD component(s) on adjacent reference
>>>>> ground plane (layer 2 for ESD on layer 1, layer 5 for ESD on layer 6),
>>>>> ground fill on deeper layer (layer 3 for ESD on layer 1, layer 4 for
>>>>> ESD on layer 6).  Ground fills connected as always using vias (some
>>>>> probably already adjacent).
>>
>>>>
>>>>  clear... except which one to actually deploy :)
>>>
>>> Well, I read about #2 in the TI High-Speed Layout but I like #1 better
>>> because we have high-frequency signals in parallel on both sides of
>>> the board and I'd feel better because I expect less cross-talk with
>>> #1.  #1 is a hybrid where we double the distance to the reference
>>> ground plane but still have ground shield between high-frequency
>>> signals that would otherwise want to radiate/couple.
>>
>>  yehyeh, makes sense to me.  okay!  it's also much more straightforward.
>
> After sleeping on it, I'd recommend making the new, deeper ground fill
> slightly larger (~5mil? margin) than the ground keepout on the
> original reference plane--as long as that's not too hard to
> accomplish.

 um... um....  noo shouuuld be fiiine....   niggles: from the last
picture you can see i have HHPD coming in at the top.  and also i
remembered, pin 19 is 5V power, that's coming in (big track, green) on
Layer 4.  however.... Layer 5 and 3 would have GND surround it, so
that's ok.

 l.