Fair point.
I should also have posted a reference to the Black Magic book, which covers this in great detail.
Amazon link: High Speed Digital Design: A Handbook of Black Magic
If you plan on doing more of this, here is one of the better textbooks on the subject. It takes a very practical approach rather than pure theory. It is geared towards higher speeds than what you are working with, but the design techniques still apply.
http://www.amazon.com/High-Speed-Digital-Design-Handbook/dp/0133957241
Your picture shows a wide parallel bus of some length. As you should know, there is coupling between the traces. This effect is where you change one signal and you see a glitch or blip on the adjacent trace.
Whether it matters depends on the design. For instance, if it's a wide processor bus where all signals change simultaneously and if you give yourself time for the bus to settle, then the coupling doesn't really matter. On the other hand, if the signals are all unrelated and changing at random times, those glitches could definitely matter. This is especially true if one of the victim traces is a clock and it glitches enough to misclock something.
You should read the Johnson and Graham book, "High Speed Digital Design" for a lot more about this subject. Yes, the book is pricey but it's worth every nickel. If it saves you a board spin, it paid for itself.
Suffice it to say that if you're designing a PCB such that aesthetics are more important than the electrical design, you're doing it wrong.
Ye, there's not enough pins for that kinda chip to be effective on all three devices.
Super High-speed stuff is pretty much black magic but from what I understand, the ESD protection is used to prevent transient voltages from possibly corrupting the signal. Think of it less as ESD protection and more like EMI protection.
Yeah, would be a good idea to add them to all inputs. What would be better - add them to columns, rows or both? As I understand it, columns put out voltage and rows sense it, so it would make sense to put caps at the rows to get rid of all the noise injected to the matrix, no?
But then, if rows sense voltage, how did the noise presumably from column output get to the row inputs, and only when some wire and a switch (open or closed, no matter) was between them? Capacitive coupling somewhere on the board and in the wires/switch? Cap between output and ground reducing HF noise that coupled through that capacitance? Odd thing I noticed when playing with caps - too big caps would trigger all the inputs from that column if a single switch connected to the column and any row was closed.
On a sidenote, I now feel I really should get a handy little tome titled High Speed Digital Design: A Handbook of Black Magic (:
Google “EEVBlog PCB design” and watch anything and everything you can find. Some of his videos are amazing start to finish, some are kinda boring, but I’ve always come away from them having learned something new.
If you want a super serious resource, I’ve heard this book is good. I haven’t read it yet myself but I hope to eventually. Also, find an eBay link if you can since it’ll be much cheaper, like under $50.
High Speed Digital Design: A Handbook of Black Magic https://www.amazon.com/dp/0133957241/
Also for a deeper dive, the go to text on high speed signals is Johnson and Grahm.
Serious answer: hire a consultant who has done this before, several times. There are good reasons why books like this one exist, and you don't want to stumble upon them in your lab & put them in series with your project completion.
I haven't yet designed boards with EMC and RF in mind. I've seen recommendations for the high-speed digital design books thrown around, though.
What are you trying to measure? Your pulse rise time will do some funny things to your results if you're not careful.
If you can obtain a copy of High Speed Digital Design, the author describes several test jigs for such tests.
google pcb design and pcb design decoupling capacitors
a lot of the manufacturers have good design notes available. if you aren't doing crazy high speed stuff, it's not too hard. high speed stuff requires the use of alchemy and black magic: http://www.amazon.com/High-Speed-Digital-Design-Handbook/dp/0133957241
The definitive work on high speed digital electrical engineering is, in fact, called the Handbook of Black Magic.
https://www.amazon.com/High-Speed-Digital-Design-Handbook/dp/0133957241
Well, depending on how you look at it, it's either Boolean algebra or black magic.
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TL;DR: You can click through to play with it and see what happens ;)
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The idea is that you set one of the A/B/C inputs and one of the X/Y/Z inputs.
There are 9 outputs corresponding to 9 different score values for a specific game.
Once you set the inputs, one of those outputs will be set to 1, denoting the score.
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The circuit uses fairly basic logic gates - AND and OR, plus one NOT.
Entire books have been written about this topic, and they sell quite briskly.
High Speed Digital Design: A Handbook of Black Magic
And of course the Electronic Design Automation industry sells CAD software which helps you to simulate these phenomena, so you can debug and optimize your design before building boards and performing tests. Prepare to write a check for $100K, or else to use flakeazoid free software from ~~ditzy grad students~~ universities.
High Speed Digital Design: A Handbook of Black Magic by Howard Johnson, Martin Graham.
Just google it :) App. note of chips vendors (e.g. FPGA), online university course notes, blogs, PCB vendors (in that order) you should be able to get some of the basics. It is not an easy topic, so stick to primary source and skips regurgitated websites such as youtube video, bloggers, ELI5 etc.
https://duckduckgo.com/?q=signal+integrity&ia=web
Intel/Altera: https://www.intel.com/content/www/us/en/support/programmable/support-resources/signal-power-integrity/learn.html
Xilinx: https://www.xilinx.com/products/technology/signal-integrity.html
As for USB3 on 4 layers, it is not an easy job. FT60X PCB Layout Guidelines - FTDI
Try to thinnest PCB as you can as this reduces the dielectric thickness. (That's why Chinese USB boards are very thin.) You'll still find that the traces get very wide to meet the impedance specs. You might need to further reduce the impedance with broadside coupled grounds. i.e. very close grounds on both sides of a diff pair. This is something you'll need to do simulation. Also keep the tracks short and if you screw up, it won't be that bad.
I added a couple of books by the same authors to the list...
The list is mainly targeted to help electronics newbies though not exclusively. It has evolved over a couple of years and will continue to evolve as I find the time to do it.
If you find this at all interesting I highly recommend the Handbook of Black Magic by Howard Johnson.
https://www.amazon.com/High-Speed-Digital-Design-Handbook/dp/0133957241
Find/download/buy this book: High speed Digital Design: A handbook of Black Magic - Howard Johnson https://www.amazon.ca/High-Speed-Digital-Design-Handbook/dp/0133957241
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Scan it cover to cover. It will pay for itself the first time you save a pcb re-spin because of something you saw in it. It has for me.
Get this book.
https://www.amazon.ca/High-Speed-Digital-Design-Handbook/dp/0133957241
SERIOUSLY - get THIS book!
Almost every PCB/EDA software doing length matching automatically so you don't need to worry about that. If you wanna know how softwares are doing it, It's more like a mathematical problem. I think they are using parametric curves like Bezier. You can calculate length of a bezier curve easily so you can match them.
https://en.wikipedia.org/wiki/B%C3%A9zier_curve
If you wanna know more about high speed pcb design, I recommend this book. https://www.amazon.com/High-Speed-Digital-Design-Handbook/dp/0133957241
Black magic? Psh, nonsense. Incidentally, if you want to learn more, I'd recommend the "Handbook of Black Magic"
The books referenced by the most presenters and PCB design conferences are Right the first time by Lee Ritchie http://www.thehighspeeddesignbook.com/ Highspeed design: A handbook of Black Magic - Howard Johnson https://www.amazon.ca/High-Speed-Digital-Design-Handbook/dp/0133957241
Note that A handbook of black magic reads like a text book, it is very long and very boring. The subject of PCB is complicated and requires an in depth understanding of the physics because just knowing the rules isn't enough convince other engineers that it's the right way to do something. More importantly, in my experience PCB design is always the least bad solution, you have to understand when you can break the rules and what the implications will be and understand if the trade off is acceptable
The handbook of Black Magic has a very good treatment.
If you're interested in high speed digital design, Howard Johnson's books are by far the most well known & a good place to start:
http://www.amazon.com/High-Speed-Digital-Design-Handbook/dp/0133957241
Johnson's High Speed Digital Design has a few chapters on power planes and multi-layer stackups, as well as being a good overall reference. The Circuit Designer's Companion is another popular book that covers PCB design techniques as well as several other electronics basics.
The best way to learn is to have your designs reviewed by experienced engineers; but if you're asking here I'm guessing you are doing this as a hobbyist. Maybe post your designs on some EE forums for review?
Also knowing 'how' is not as useful as 'why', ECAD tools generally are different enough that the specifics of how to accomplish something are not the same. Which tool do you use? Most have online user groups or forums for specific questions.