--- crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68
On Mon, Dec 18, 2017 at 2:55 PM, Richard Wilbur <[email protected]> wrote: > On Mon, Dec 18, 2017 at 3:02 AM, Luke Kenneth Casson Leighton > <[email protected]> wrote: >> On Mon, Dec 18, 2017 at 7:02 AM, Richard Wilbur >> <[email protected]> wrote: >>> On Sun, Dec 17, 2017 at 11:34 PM, Luke Kenneth Casson Leighton >>> <[email protected]> wrote: >>>> On Mon, Dec 18, 2017 at 6:31 AM, Richard Wilbur >>>> <[email protected]> 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. _______________________________________________ arm-netbook mailing list [email protected] http://lists.phcomp.co.uk/mailman/listinfo/arm-netbook Send large attachments to [email protected]
