3 ms·
“ Another curiosity hidden in the circuit board is this wiggle on one of the traces. It contains a tiny detour to make sure it’s the same length as its paired t
by mensetmanusman 3y ago
“ Another curiosity hidden in the circuit board is this wiggle on one of the traces. It contains a tiny detour to make sure it’s the same length as its paired trace, which is especially important when dealing with extra-high-speed data transmission.”
A wiggle that small is adding picosecond delays. I’m surprised that’s necessary. Cool!
- addaon 3y agoThis comes up all the time in the context of DRAM routing. See e.g. the first image at https://resources.altium.com/p/pcb-routing-guidelines-ddr4-memory-devices https://resources.altium.com/p/pcb-routing-guidelines-ddr4-m....
- mensetmanusman 3y agoOkay in this case impedance matching is more important than the time delay. Thanks for the link :)
- ivanjermakov 3y agoToday I learned! I'm curious to see approaches to solving optimal pathing of traces to keep them equal length.
- _moof 3y agoThere's not much to it. You route them without worrying about equal length, and then your EDA tool adds serpentine tracks to the shorter one to match its length to the longer one.
- simondotau 3y agoMy (deeply uninformed) guess is that it probably wasn't absolutely necessary, but would be one among a hundred tiny details which improves resilience. There was space for it. And it has a $0.00 unit cost. It'd be more surprising if they didn't do it. For Apple, perhaps the most economically exposed to customer problems of any major tech company, and has enough scar tissue from past failures, it's not surprising that their products tend to feature first class electrical engineering. Their DC chargers are widely regarded as among the best in the industry.
- deleted 3y ago[deleted]