• SpaceNoodle@lemmy.world
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    1 year ago

    A millimeter is huge in these situations. USB3 requires 5 mil tolerances, just over 0.1 mm. This scales with the inverse of data rate.

    Electronics are so fast that we gotta take the speed of light into account. God help you if you put too sharp a bend in a trace, too …

    • TimeSquirrel@kbin.social
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      1 year ago

      Haha, I’m still over here messing with 10/100 Ethernet and USB 2 on my home projects. I’m used to bigger tolerances than the truly high tech stuff.

      • SpaceNoodle@lemmy.world
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        1 year ago

        Same, but now I’m working on very high-speed stuff for work and starting to get into that hobby-wise as well. Just yesterday had a conversation with a colleague about how things are getting too small to hand-solder.

      • GluWu@lemm.ee
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        1 year ago

        My dedicated AI machine uses 1866mhz DDR3. Consumers don’t know what they need and will buy whatever the latest new thing is. Smart phones are so dumb. Like wow, your brand new $2500 phone has a benchmark 4x faster than my refurbished $250 phone. Now tell me what you do with all that power. “…well I save 27ms per Instagram post which adds up with how much I use it”. I want to run headfirst into a brick wall.

      • flying_gel@lemmy.world
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        1 year ago

        A millimeter i.e a thousands of a meter.

        edit: I was wrong, confusingly enough it is a thousands of an inch

        • Aceticon@lemmy.world
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          1 year ago

          In the design and manufacture of PCBs (aka circuit boards) a “mil” is a one thousandth of an inch, so it makes sense that’s what is being used in this context.

          Also the maths check out: 0.005 inches is equal to aprox 0.12mm, “just over 0.1mm”.

          • flying_gel@lemmy.world
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            1 year ago

            I stand corrected, and I see I didn’t read the comment thoroughly enough either.

            Colloquially as a non-pcb maker I would use and hear the term “mill” as short form millimeter so I assumed it was that.

            so TIL :)

            • Aceticon@lemmy.world
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              1 year ago

              Yeah, I found it wierd too when I started designing PCBs (as hobby) that “mill” actually stood for thousanth of an inch.

              Probably for historical reasons, there are tons of things in the older domains within electronics that are based on inches rather than metric units: for example the spacing between the legs of a microchip in the older chip package formats (so called DIP, the ones with legs that go into holes) is exactly 0.1"

              The sizes in more modern electronics isn’t usually based on inches anymore, but circuit boards are old tech (even if done with new materials) so there are still a number of measures in there which are based on inches.