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Would it be possible to make a USB Hub from scratch? Like, designing a PCB, and hand soldering components on to it? What microchip would I have to use as the controller? Is there a simple controller chip I could use for, say, a 4 port hub? I know I'm getting a bit hopeful here, but are there USB hub ICs in the DIP package?

skillz21
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    Depends on your understanding of 'complicated' – Peter Smith Jan 14 '18 at 17:12
  • @Peter Smith Lots of SMD traces and components is complicated... – skillz21 Jan 14 '18 at 17:16
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    You can, but what's the point? A conventional MCU is not involved, instead a special purpose hub IC has almost everything except for supply and support components. This wouldn't really seem to make any sense as a project unless you are prototyping a product, or need to combine a hub with other capabilities. Even then (for example, contemplating a production test rig which measures device power currents) it may make sense to buy a hub and trivially modify it. – Chris Stratton Jan 14 '18 at 17:54
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    Ummmm "designing a PCB online?" Why use some wishy washy web majiggy instead of a real design program? – JRE Jan 14 '18 at 18:04
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    @JRE: the web one is already installed and runs on linux/chromeos/mac/etc... – dandavis Jan 14 '18 at 22:08
  • Microchip??? Heck, use discrete transistors. – Hot Licks Jan 14 '18 at 22:26
  • Yes, someone I know made USB hubs as business cards. It's not difficult considering there are already-made USB hub chips and you mostly just have to wire them up to USB connectors. – user253751 Jan 14 '18 at 23:17
  • USB 2 hubs aren't that hard to create with modern USB hub controller ICs which do pretty much everything for you. I've had good time with USB4604. USB 3 hubs are tougher proposition. – Nick Alexeev Jan 15 '18 at 00:52
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    ... having said that, I'm closing the question as *too broad*. For future reference, see this meta post: [Why is “Is it possible to…” a poorly worded question?](https://softwareengineering.meta.stackexchange.com/questions/7273/why-is-is-it-possible-to-a-poorly-worded-question) – Nick Alexeev Jan 15 '18 at 00:56
  • @NickAlexeev, did your PCB pass eye diagram template and differential impedance test? – Ale..chenski Jan 15 '18 at 01:23
  • @AliChen I did look at the eye diagram. I didn't test the differential impedance, but I've done the impedance controlled differential pair routing (in Altium), and I used the impedance controlled PCB fab. – Nick Alexeev Jan 15 '18 at 01:29
  • The question is closed for good, but the reason should be total luck of research. Yes, there are at least 7 reputable companies who make "microchips" for USB hub controllers: Genesys Logic, VIA technologies, Renesas, Microchip, Texas Instruments, Cypress, Fresco Logic,. And who knows how many no-name clones from Asia. – Ale..chenski Jan 15 '18 at 01:57

3 Answers3

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Sure, I do it all the time — custom hubs for embedded applications. I use chips from Cypress, but they're certainly not the only game in town.

You do need to pay careful attention to the layout of the traces associated with the crystal and the USB data pairs (impedance-controlled). And some chips have a thermal pad that's difficult to solder without hot-air tools.

Dave Tweed
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With some usb hub ICs it's as simple as the ic, a crystal, and a few passive components. Easy to design if you feel like taking the time. A single sided PCB is possible too.

Here's a simple (two-sided) example PCB:

4 port USB hub PCB

Bryan K
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Passerby
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    That's not a single sided PCB. It may have all of the signal traces on the top, but there are plenty of vias evident and no evidence of distributing *both* VBus and ground to the port connectors on the top layer. If there were, we'd see distinct traces on each side of those mounting holes in between the connectors, instead of one big copper pour. – Chris Stratton Jan 14 '18 at 17:58
  • If you say so... – Passerby Jan 14 '18 at 19:35
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    Well, how do *you* think they're getting both 5v and ground to all those connectors? And why do you think the upper trace from that multilayer ceramic near the UC5 label terminates at a hole in the PCB? It does seem like the IC has been designed to permit a very clean routing of the signals and perhaps the back is all ground or power plane - but it's not single sided. – Chris Stratton Jan 14 '18 at 19:39
  • It is not possible to make a good USB 2.0 hub (with 480 Mbps mode working) even in a two-layer standard (1.6mm) PCB, simply because the USB traces will be to wide to meet 90 Ohm differential impedance. – Ale..chenski Jan 15 '18 at 01:28
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    @Passerby What IC did you use for this? – skillz21 Jan 15 '18 at 02:24
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    @skillz21 this is not a custom project, but a teardown photo likely of a very low-cost hub. – Chris Stratton Jan 15 '18 at 02:54
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    [DIY 4 port USB Hub, hand-carved single-sided PCB!](http://www.instructables.com/id/Four-port-USB-hub/) – Bruce Abbott Jan 15 '18 at 04:03
  • Exactly. He's trying to make it seem like it's nothing that can't be handled by jumpers or 0 ohm smd resistors. https://lh5.googleusercontent.com/-OdONgudIK84/TqQvYfr3WuI/AAAAAAAACQc/5EWUHM1qmV4/s912/IMG_5134.JPG 100% via less one sided board. – Passerby Jan 15 '18 at 04:53
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    @Passerby He's not saying that it's impossible to do it on one sided board. He's saying that the image you have in your answer is double sided, which you are *implying* is single sided. – Harry Svensson Jan 15 '18 at 17:22
  • @HarrySvensson I wasn't implying anything like that. It also has a 5050 led on there, is it implying that all usb hubs need leds? – Passerby Jan 15 '18 at 21:15
  • @Passerby Keep up the good work. – Harry Svensson Jan 15 '18 at 21:18
  • I've edited the answer for clarity. – Bryan K Jun 02 '18 at 20:54
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I have done this using TUSB4041I but had to use a professional assembly house to populate the board, it is incredibly fiddly.

beerbug
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  • These chips are entirely within the range of careful hand work. A microscope will be a help, but it's possible to do it with only a 10x jeweler's loupe for post inspection. The key is to solder just one corner, check alignment, solder the opposite corner, check again, etc. You can also cut a thin strip of tape and put it diagonally across the chip to help with those first two pins. – Chris Stratton Jan 14 '18 at 18:00
  • Yes i agree some can do it. That design had many discrete components as well though, 0603 size. At my age though hand steadiness is a major problem. – beerbug Jan 14 '18 at 19:19
  • It was a one off and was assembled by hand but by someone more dexterous than I with a few helping gadgets. – beerbug Jan 14 '18 at 22:20