On Fri, Mar 16, 2012 at 8:37 AM, Werner Almesberger <wer...@almesberger.net>wrote:
> In USB, I only found one piece I'm not sure about: the internal connector > J24. > > - considering [1] (figure 10 on page 14), shouldn't we mark pin 9 > as NC ? > > - pin 9 and 10 are marked as USB shield. The above reference has a > completely different idea about it (overcurrent). Shouldn't we > NC it too, and leave shielding aside ? > applied temporarily to: http://downloads.qi-hardware.com/people/adam/m1/tmp/m1r4/USBIntPorts_20120316.pdf > > If you can find one of those little passive commercially available > header to USB A boards (to plug on the mainboard of a PC), perhaps > you could check where they connect the shield. > I don't have a PC here, I may go somewhere to check how that USB cable connects shield ground and signal ground. > > - if we decide to keep shield on J24, wouldn't it be better to > ground it separately it from the external shields ? > It's true that pin 9 is KEY, pin 7 and 8 both Ground, no else pins to conect directly an external shields. But I think I can imagine page 16 of [1] for USB combined cable itself would be on one side wafer with connection together with whole cale shielding and one signal ground. or maybe two side. It's just guessing though, will see. > > [1] > http://www.usb.org/developers/whitepapers/power_delivery_motherboards.pdf > (available in the bookshelf as "usbpwr") > > You were looking for a header that already comes polarized. I think > this one may fit: > > > http://search.digikey.com/us/en/products/TSW-105-26-H-D-009/TSW-105-26-H-D-009-ND/2685930 > > Non-stock, but only takes one week. Oh, and it's heavy metal ;-) > marked this p/n in sch. Thanks, - adam
_______________________________________________ http://lists.milkymist.org/listinfo.cgi/devel-milkymist.org IRC: #milkymist@Freenode
