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

[Luke Kenneth Casson Leighton]

On Mon, Dec 18, 2017 at 6:03 AM, Richard Wilbur
<richard.wilbur at gmail.com> wrote:

> So it might be easier to just put a ground keepout on layer 2 under
> the ESD component on layer 1 and a corresponding ground fill on layer
> 3.  Likewise a ground keepout on layer 5 under the ESD component(s) on
> layer 6 and a corresponding ground fill on layer 4.

 yehyeh.  ah.... do you mean the *whole* component?  conflicts with
putting keepout(s) under individual pads...

> I was recommending just under the ESD pads specifically for the
> high-frequency differential signals.

 conflicts with words above about "GND keepout under ESD components"...

>>
>>> Likewise with the connector, I would put a ground keep out under the
>>> lands on layer 2 (probably best to just draw a keepout under the whole
>>> connector on layer 2)
>>
>>  including for the HSCL, HHPD and even the GND pads? of course there's
>> VIAs connecting the tracks in between the diff-pairs
>
> Wouldn't have to I suppose but the idea is to move the ground further
> away from the high-frequency pads to reduce the capacitive coupling
> thus increasing the impedance.  Thus I think it's probably best to
> extend the layer 2 keepout under the whole connector.

 got it.

l.