[Arm-netbook] HDMI High-Frequency Layout: Recommendations Vias Moveable?

[Luke Kenneth Casson Leighton]

http://rhombus-tech.net/allwinner_a10/news/eoma68-a20-275-layers126-illustration.jpg

ok so this shows what's going on: already those GND vias have been
moved significantly away from the pads associated with them (the ones
for the 5V0) and those are MAJOR power (2A) so it's really rather
important to have them close.

now,  what i _could_ do is turn the one connected to IPSOUT round by
90 degrees (anti-clockwise) and move it upwards, making use of the GND
vias near the HX2P/N diff-pair vias.  then there would be room to do
the same thing with the 5V0 power in one as well.

one thing: in speaking with mike from the factory, he's been tracking
the price of capacitors now, which have showed a FIVE TIMES increase
in price over the past six months.  0.1uF, 10uF and 100uF capacitors
in particular, the prices have gone INSANE.

the reason?

f*****g apple's f*****g phones.

the response: every supplier in shenzhen is HOARDING supplies and
asking FIVE times the normal rate.

this isn't going to calm down any time in the next 6 months: it's
going to take apple finishing the insane glut of orders for their
latest phone, plus a few months extra, before prices return to normal.

so in the meantime what i think i will do is, put in double batches of
*smaller* capacitors, with unusual values (three 33uF instead of one
100uF), which is, from what i've read, a better way to ensure stable
power *anyway*.

as in, two 4.7uF capacitors stabilise power much better than one 10uF
capacitor because of the increased current capacity of two caps -
something like that, anyway.

bottom line: if i shuffle in two 0603 4.7uF caps as a replacement for
the 0805 10uF, it reduces the cost on the BOM based on current
pricing, improves power stability, and also means that those VIAs in
the middle there can entirely be removed.

l.