hiya richard, so how you getting on? --- crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68
On Fri, Oct 13, 2017 at 1:56 AM, Luke Kenneth Casson Leighton <[email protected]> wrote: > On Thu, Oct 12, 2017 at 9:16 PM, Richard Wilbur > <[email protected]> wrote: > >>> whoops.... :) 89 ohm... 50 ohm. 89 ohm... 50 ohm. oops... :) >> >> Well, if the reported impedance is the single-ended impedance >> of those lines we have considerable margin to burn and should >> aggressively pursue the taper structure and bring in the keepouts at each >> end. > > i sort-of understand that. am i right in thinking: at the ends we > have to treat them as single-ended, and achieve a sngle-ended > impedance of 50 ohms, but 100 ohms for the diff-pairs. > >> For the geometry that fit our constraints, we calculated a single-ended >> impedance of ~72 Ohm and differential impedance of ~111 Ohm (which >> corresponds to a tolerance of 11%). > > ok so 72's not really very close to 50 ohms... interested to learn > how that can be achieved. > > l. _______________________________________________ arm-netbook mailing list [email protected] http://lists.phcomp.co.uk/mailman/listinfo/arm-netbook Send large attachments to [email protected]
