USB Hub Design Walkthrough - Phil's Lab #86
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- Опубліковано 20 чер 2024
- How to design your own USB 2.0 high-speed, four-port hub. From system overview, through to schematic and part selection, to PCB design and layout.
Altium design review competition: www.altium.com/altium-365/des...
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[TIMESTAMPS]
00:00 Introduction
00:30 USB Hub Basics
02:06 Altium Designer Free Trial
(Schematic)
02:24 Block Diagram
06:01 Power Supply
07:57 USB Host Connection
09:37 Decoupling
10:36 Crystal and Load Capacitors
11:27 Strapping Pins
13:25 USB Devices Connections
14:28 Load Switches
(PCB)
16:04 PCB Overview
17:44 Stack-Up
18:34 Controlled Impedance
20:19 Diff Pair Routing and Matching
22:32 Reference Planes and Transfer Vias
23:47 Misc. USB Hub Connections
24:37 QFN Decoupling
25:40 Power Routing
26:52 Misc. Points (Cap Placement, Silkscreen, Mounting Holes, ...)
28:48 Short Test/Demo - Наука та технологія
For the sake of time, I used Altium's Content Vault/Manufacturer Part Search Tool for the symbols and didn't draw some part symbols myself. As such, the ESD protection symbols aren't quite right (although the pinout + footprint + functionality is still as it should be) - there are four diodes in the package -> Pins 1 and 6 are common, pins 3 and 4 are common.
A great example, why you should pretty much always create your own symbols, footprints, and libraries :)
Hi. Can I please know are those USB ports controllable? Can we enable and disable them separately?
github for project?
Oh, I just noticed that 😁😁the ESD protection Diode D6 Symbol is for USBLC6-4SC6. and Find Your Comment.
BTW I Love Your Content.
YOU MAKE MY LIFE EASY.💕💕
Hey Phil, it would be nice if you could post the Altium 365 viewer link to the projects in the video description. Or is that a license problem? So I could take a look at the circuit diagram again in peace
Great video. Would love to see a USB 3 Hub design with Type C connector. Similar in principle but the super speed differential does complicate things a bit.
Thanks! Yes, will be making a video on that in the future. Actually have a design I'm currently working on that features USB-C and a USB 3 SS hub.
@@PhilsLab I was wondering why I rarely see USB-C hubs (with HDMI, PD, Ethernet ...) that feature additional USB-C ports. Most of them just carry USB-A ports. Is this a hub chip limitation? Must be a cost consideration or some obvious reason that escapes me.
@@ligius3 when you use Alternate functions of USB3 (DP, etc) it has to physically reassign differential pairs from USB to this interface, so you probably loose the ability to mux several downstream ports into this one upstream
@@ligius3 I have some hypotheses about why there are so few hubs with USB C ports. The core reason is that the Amazon reviews will be full of people complaining about why the hub doesn’t “work right”.
People will plug USB C to HDMI adapters into the C ports, and they won’t work (unless the hub has much more expensive electronics)
People will plug their power supply into the wrong port and wonder why their laptop doesn’t get power (unless the hub has way more MOSFETs to enable PD input on any port)
People will plug their iPad into the USB C plugs and complain that it charges really slowly - the laptop will only provide 15W total, so if you spread that among four ports, that’s very low power per port.
I’m not certain these are the reasons, but I’ve seen the number of bad reviews by people who don’t know what the hub is supposed to do. If I worked for a hub manufacturer, I’d be very cautious before making a multiport USB C hub.
@@PhilsLab I am reading all the time that USB3.0 requires at least 4 PCB layers to comply USB specs so I would really like to see such a PCB design (+schematics of course). It by the way, it seems nobody on youtube is covering this topic much, everyone just focus on USB2.0. So I am sure it will be valuable for your channel too :) Looking forward to the video!
Really appreciate the time and effort put into these videos! Really helps me to understand core principles and keep me motivated for my own projects ;)
This has been my fav channel recently !
Good job on the video. I worked on the USB Media hub ( fancy word for the USB charger) for the RAM1500 truck in around 2015 at my last job. it too was based on a microchip USB hub, but need a bunch of extra protection and lighting for the rings around the connectors. in a car, thanks to the Apple lighting connector, which could accidently touch inside of a 12V lighter plug, you have to be able to withstand short to battery on all lines and charging at higher than 500mA requires some smarts to negotiate the higher current. I unfortunately never finished the design, as I changed jobs, but did do all the initial design work for it :)
Just awesome. I always learn something new from you videos!
+1 on the ferrite bead video..
Your videos are really informative and of great quality.. keep it up 👍
Thanks for your video! Very helpful for me.
Great timing- I just ordered some boards I made using the USB4604 IC! I’ve learned so much from your videos, and I’m pleasantly surprised that my schematic looks pretty similar to yours haha!! I’m using bus power and fuses instead of load switches, and not sure i did impedance matching properly… but I picked up some tips from this video that I’ll be sure to implement on my next revision!
Thanks, Seth - glad to hear that!
Awesome video as per usual.........cheers.
very great info and video. thanks!
Great lesson. Thanks a lot
Thank you for the very informative tutorial!
I have no idea why I’m watching this but it IS FASCINATING. I guess I enjoy listening to smart humans talk through their ideas haha
Educational. as always. Tnx
Amazing video, Phil.
I wanna learn more about the scenario how to connect the USB chassis ground?
When should I connect USB chassis to the system ground or just split it with a capacitor and larger ohms of resistor between system ground?
Nice video, well done, thanks for sharing :)
Subscribed long ago
Great channel
Keep it up 👍🏼
Thanks, Jack!
Great vid. I'd love so see the design expanded to give individual port power control by microcontroller. Maybe a 7-port hub in which one port is delegated and internally connected to a uC handling USB-HID transactions from the PC in order to manage the enable pins of each load switch but still maintaining the hub ic authority over power negotiation and over-current detection. Such commercially available managed hubs are really expensive so I think this would make a great DIY project. Those cheap hubs with individual port power physical latching switches are pretty bouncy and nasty - and of course, not remote. Having tried this myself I found that port power switching without switching the data lines was reliable for all bus powered devices but that for self powered devices, properly sequenced power AND data switching was required and that the removal of both was enough to put many self powered devices into sleep mode. My inspiration was the Yepkit YKUSH and YKUSH3 switched hub boards (PIC based). My future intention is to use ESP32-S3/S2 rather than PIC so I have the option of Wifi control and power monitoring.
amazing work, it really helped me alot to understand
Thanks!
"Welcome back, may I help you"?
I had to smile...
Please make a video on how you calculate the passive filter components...
And as always it really helps a lot... Thank you very much
I've been doing boards for about 30 years and constantly learn more from your videos. Curious, the USB chip bias resistor has an increasing trace width, 23:50, why?
It's called necking, It's commonly used to go between ics or component pads while still maintaining a large low impedance track and routing in tight spots
Dang you’re underrated as. I would build this if I had the stuff but maybe not yet
Great tutorial!
How much cost did the double-sided assembly add to the board? I face issues with decoupling and routing QFN packages because of their fine patch but if I can move decoupling capacitors to the bottom layer with minimal costs, this would make routing much easier.
One of the design for EMI/EMC tips that I came across was to keep connectors to one side of the PCB or at least one corner. The first thing that came to mind was accessories such as converters and hubs since they, most of the time, have connectors on opposite ends of the PCB which is the worst case. How would you minimize EMI issues with such accessories?
Lastly, I am looking forward to the FPGA design course. Is there an estimated release date?
Hey phil, great video as always !
question : The USB2514B Datasheet says that it contains ESD protection so is it necessary to add them ?
Im very happy to see a micro USB-B!
Interesting you've used this in in the past in combination with a Xavier, im currently also working on a ANX Xavier carrier board.
I'd be interested to see your approach to such a board.
The Xavier carrier board was a work-related project, so I'm afraid I won't be able to share any details on the channel. There wasn't too much to it though, other than power supply sequencer and routing out the various interfaces.
@@PhilsLab I understand that you are not able to share that. Thats a shame since I would have liked to see how to approach such a project mechanically, since the board is supported only by one card edge connector and needs to be able to dissipate up to 30 watts.
Im my case there is also a lot of high speed signals to route since the board is connected with a coprocessor and two FPGAs via PCIe.
Either way, keep up the great videos! Your channel helped me a lot when getting into high speed PBC routing, especially the "FPGA + DDR PCB Design" video and the relatively new "FPGA + PCIe Hardware Accelerator Design" video, so many thanks for that!
I am an electrical and electronics engineering PhD student, and I would love to chat with you about learning sources.
I learn from your videos so much, thank you for that, but your knowledge seems advanced to me, and I really want to know the sources of knowledge so I can develop myself more and more.
Thank you for your amazing videos
Really, good job!❤
I'm wondering if I can install the same circuit for each input of that one .. like a multiplexer?
Geat video! Your videos always get me to a new state. Will you make a video about ethenet switch?
Thank you! I'll be making a video on 'generic' MAC PHY RJ45 routing at some point in the near future.
Great video sir, This has been very helpful. I was wondering if you could make an updated video for usb 3 hub designing based on USB5744 IC. I was looking for a trustable resource for this and any support you could provide regarding this will be extreamly helpful
Hi, first of all great video I've learned a lot. I'm a newbie to electronics and I noticed you put a lot of emphasis on ESD protection so I searched for it and found your video about it (#75) I noticed you added ESD to your molex connector on that project, but you didn't add a TVS diode to the DC on this project, wouldn't a surge kill the linear regulator?
Asking as a newb would you say ESD protection is something you should always add on every design?
Thanks
Waiting for the ferrite bead video :)
Hi Phil. I love your videos, and I’ve learned so much from your channel. I wanted to know if you had any resources in regards to component management with Altium. Im on MITs FSAE team and I want to design boards next year for testing from JLC quickly, while main boards from PCBWay. Currently we just use random components from the manufacture part search for everything, so how would we go about more structure in managing parts. Thanks!
Would love to see a project using some MIL (military) specs and / or high temperature considerations.
Thanks for the videos, excellent work as always!
2nd this. It does of course depend on Phil's experience with respect to MIL spec specifically, but looking at a more 'generic' high temp / specific environment or even expslosive environment would be great to know (even for someone who has no need to know this like myself!).
Thank you, Leo! I'm afraid I'm not too familiar with MIL spec designs - but I'll definitely be making a video on thermal aspects of hardware/PCB design.
Leo, I could do you one but it'll take 10 years and I'll need $50,000 to write the spec first! 🤣
Hey Phil, I have been working on a design that I’m a bit stuck on. Basically, I have a board that I want to be powered from a 12v battery for running, but also from USB for testing/programming. I am using a TPS54331 step down converter and am not sure how I would prevent backfeeding either the USB or TPS54331. I think a diode would be too much of a voltage drop
Hi Phil, awesome design! Can you do a project on a ethernet switch pcb? Maybe use an unmanaged switch ic and show how to correctly set up the strap down design? Also, it would be really helpful to see you do to the routing of ethernet including magnetics. I sometimes feel overwhelmed when looking at the datasheets. ;D
Hey, Actually working on a project featuring an Ethernet switch IC. However, I'll probably just be covering the 'classic' Ethernet PHY + magnetics + jack (or integrated magnetics) in a future video, rather than the switch.
@@PhilsLab seconding the call for ethernet switching ;-) I'm working (hobby) on a eurocard rack system to condense all the "boxes" on my bench into one unit (soldering iron, multi-meter, function gen, scope etc) and I'm trying to work out what to use on the backplane. I'm thinking usb and ethernet should cover most bases. Ethernet on a backplane/PCB to PCB seems pretty lightly covered.
Would love to see something like this, but for ethernet, even a 10/100 Mbps would be plenty. Something like that would be plenty for some simple modbus over tcp/ip.
Now do a USB4 Thunderbolt 10000000Gbit throughout. Love to see the PCB and routing.
Great video again!
If the input was type c and it had PD would u consider a buck to 5v instead of the external 5V? (assuming all slave ports are USB 2 and you can deliver all the needed power via PD)
Some video ideas:
1 Setup review : you have so many hubs i became curious of the reason why
2 In depth audio design since you inspired me also into trying audio .
3 Maybe something relating to MIPI or some other video camera interface?
4 Maybe how does one find a interesting job like you found (as in company)?
USB-C as far as I understand is like a conventional USB that requires a separate set of circuitry for serial data transfer and power delivery. For the power delivery circuity there are a few circuits out there that integrate a pd controller into a buck converter or switched mode buck boost converter. This will step down the voltage to an additional battery charger circuit that will connect additionally to a buck converter to 3.3V or 5V depending on your circuit requirements. The great thing about these new ICs is that they can be configured for fast charging LiPo batteries which are treated as conventional Li-Ion batteries in the datasheet but have much higher charging current rates.
Could you please do a video on building USB HID circuit example?
Hey Phil, great video as always! I saw this video a few months back and have decided to learn more by following along and designing my own board.
Quick question though, does adding the top copper pour make this a "co-planar" differential pair? Or is the gap between the pour and the differential pair too large to not make a difference? I also noticed the physical board you demonstrated at the end of the video didn't seem to have a copper pour, is it by design?
edit: fixed typo/grammar
Thank you! Rule of thumb is that if your clearance between trace and coplanar pour is ~3x dielectric thickness, then impedance won't be significantly affected.
Depending on the design I'll add copper pours or not, hard to give a general guideline I'm afraid.
Thanks@@PhilsLab! I appreciate the response, and look forward to your next video!
Hey Phil, thanks for your invaluable content. I'm currently working on my first PCB project in KiCad and I'm having a hard time looking for a proper protection circuitry for a USB 2.0 power supply board (only power, no data) with 3.3V (LM1117) and 12V (TPS61087DSCR) outputs. This project is aimed for college students so I consider that short circuit and overcurrent protections are mandatory.
I'd be happy if you could recommend any ideas or resources to learn about how I could include such protections.
Thanks bro!!!
Hi, I just watched your video and it was very informative. I am currently working on a board that focuses on powering 10 devices via USB-C. Now I would like to add support for a PC connection to send data to all connected devices while providing up to 1.5A of power to each device for charging. After watching your video, I have two questions: first, can I just leave out the load switches? Because I already have the outputs of my 10 DC/DC switches clamped to 1.5A, or is the USB-C port limited to 500mA for data hubs (so data transfer and "fast" charging can't happen simultaneously)? Secondly, to increase the number of connections, can I just route the host connection back into another USB hub controller to add up to 7 devices for example? 😀
Amazing video Phil, as always. I just wanna know doesn't your top ground plane change the impedance of your differential pair? In previous videos you mentioned that you don't like to put a GND copper pour on top when routing impedance matched pairs. Thanks in advance. Love your videos.
Thanks, Petr. If you're gonna pour copper around controlled impedance traces, you need to keep clearance (e.g. via a specific design rule) between the two. This is mentioned in the video as a little text note (seen at 20:13). For those traces I keep approx. 5x dielectric thickness clearance between copper pour and controlled impedance traces. This is normally sufficient.
@@PhilsLab Oh, I didn't notice the text when watching. Thank you for the answer. I will keep this in mind in when creating my future designs.
I missed that note as well!
I designed a PCB based on this design with only a few differences but my top ground pour wasn't adjusted to give 0.5mm clearance. On one boards its "device not recognized" and on the other I get nothing from my PCB. Are these the sorts of errors one can expect from an impedance related problem?
(side note: I have access to a microscope and have checked my connects very carefully).
Would sandwiching a ground trace between two differential pairs help with cross talk? Would the ground act as a shield between the two signals?
Hi Phil! What about if u want 15 ports for example. Can you add another hub ic for each output??
NICE
Hi Phill, I want to know if the Mixed Signal Hardware Design with KiCad course is subtitled in Spanish ? Thank you;
Hi Phil does the TS3USB31E 1-port switch ic and the load switch ic mentioned in this video do the same purpose?
Great video as always. One question, it almost looks like you have islands of copper pour that is not stitched between the output caps and the Full-size USB connectors on the top layer, is this a rendering problem or is those sorts of islands not a problem for this sort of design?
Thanks, Biko - yes, good catch. I used the automatic via stitching feauture, which means the grid was too course to pop a via in those positions. I didn't check in detail afterwards so missed it! In any case, for that size of copper island, it won't do much/any harm.
Great video. I was wondering if in the future you would like to make a video about USB switch a device that with a press of a button you can share 1 usb to multiple devises by disconecting it from device A and connecting it to B from B to C ... etc every time you press the button i believe it would be useful to many ppl and its not an easy thing to find commersially with more than 2 slots (at least in my country) and it would be useful for my server and for many ppl that like DIY stuff
Great applied introduction to some more advanced board design techniques (impedance control, delay matching, stitching, etc). One question I have: what did you pay to have these boards manufactured? I followed along with this design, and somehow ran up a bill of over $200 USD which seems excessive. I'm using the largest minimum trace widths available on PCBWay, and no special features. I'm sure I can go through the BOM and find cheaper parts, but it seems it cost around $130 USD just to manufacture the boards. Is that typical or am I missing something?
I was working with the 2 port version of this chip to build a device that would combine a USB sound card with USB serial port on a single pcb connected to the host PC, but I kept having problems where if I didn't reset the Hub chip after attaching to the PCB, the USB sound card would never show up. Any ideas why? Edit: Some additional info, I had both devices permanently connected to the hub on the board, but I also had set the flags to tell the hub chip that, so I was kinda stumped.
Hi Phil, thank you so much for your video's! I learn so much from them and I absolutely enjoy working on embedded systems/PCB's.
I was wondering if for a future video you could work on a topic that involves rechargeable batteries (lithium ion), protection IC's, charging IC's, something like that. Nowadays many devices are wireless on rechargeable batteries and I sometimes struggle to properly implement this in a safe way, often it seems people don't care about safety and protection IC's at all. (Maybe even something solar powered?)
I was also wondering if you could show us how you actually find/source components, how do you find that specific IC, what do you look for, what do you filter for, etc. Component sourcing is a very important part of creating a proper system. Thanks once again!
Thank you very much!
Yes, that's something (battery-related ICs) I'd like to make a video on in the future, although I'm not sure when.
Regarding component sourcing, that's covered in part in my mixed-signal hardware design course. It's especially difficult these days due to the part shortage as well :(
@@PhilsLab Thanks a lot! :)
I'll have a look at the mixed-signal hardware design course as well!
Any updates on when the ferrite bead video will be coming?
can we cascade couple of those USB2514B chips to increase the port bumber?
When is the ferrite bead video going out?
Hey Phil great job as ever, thanks for the video.
Is it possible to make this board on a 2-layer PCB, because it has few components on it?
I like such pretty useful things for education purposes, the outcome can be used daily, nice!
if it's possible I would love to see a BMS and lithium battery charger up to 6S with balancing for DIY power bank for laptops (19v 5A )
Anything with controlled impedance requirements is a bit more difficult to pull off with a 2 layer stackup. Due to the increased dielectric height in 2 layer boards, controlled impedance traces are much wider, as a good rule of thumb, a 50 ohm microstrip in FR4 with 60 mil dielectric height would be about 120 mils wide which would make routing to small IC pins impossible without large impedance discontinuities. So, increased layer count is not entirely about routing density but also creating a dielectric environment that allows for realistic trace geometries.
@@CSFitness1 thank you , then isn't there any optional dielectric height, what if I use thinner dielectric? would it be possible to meet the requirements?
@@myetis1990 you can specify your stacking layers, however, the board will be very thin in your case. We have a couple of boards designed with two-layer thin stacking. They break all the time if you gently twist the board.
Do you route all signal traces as 50 ohm controlled impedance?
@PhilsLab
How do the volt and amp capasaty of a USB hub effect the performance and data transfer rate of a hub ?
Where can I would download the schematic so that i can follow slower the video and each step at my time?
How much extra circuitry would be involved going to usb3 source side and then feeding each usb device side to a sata converter. Essentially a usb3 hub to 16 or 32 x sata3 data connections only.
This amount of SATA devices is a bad idea even via PCIe, let alone USB..
what about a usb-c/thunderbolt switch? I would love to be able to switch back and forth between my pc and macbook
Interesting. Can I just add on a sata controller? For 2-4 drives.
I tried finding some but they cost a load of money and are very difficult to ship to me.
The Best
Thanks! :)
i want to make a charging dock for ambient nanolockits. i can CAD and CNC the body of it, that part's fine. but i dont get the circuitry at all. would this be a lot easier if i dont need to transfer any data? do you still need a ton of components to split the power pin into six?
How long does it usually take you to design a board like that (from the idea to the manufacturable design)? 🤔
Your videos are so nicely educational 😊😻.
Thanks, Theo! This demo board took a couple of hours (4ish?).
What resource do you recommend to someone with familiarity to electrical concepts but new to electronic circuit board design?
This channel - check out the 3hr KiCad or Altium vids for complete walkthroughs :)
Doesn't matter for this design, but for speeds greater than USB 2.0, it's a good idea to keep the silkscreen off the diff pair traces.
You should make a Rockchip version of a Raspberry Pi!
Can you add a small led bulb to show that a device is connected to one USB port?
I thought due to usb specifications, that blue connectors should be used at least for USB version 3?
That's correct. At the time I had some of those as spare parts lying around, so ended up using them for that hub board I made ~2 years ago. Not to USB specification of course but useful just to test the IC and peripheral connections.
@@PhilsLab okay, totally makes sense. 😎👍
Can you do a 4 port usb2 hub to a usb3 port, for the speed to get into the computer.
hallo is it posible to use sata as a host and 4 usb out(for to make a usb hub cady)
Is there a way to remove all power through usb and just have data?
Would it be possible to make USB over fiber for long distances? I got a janky 50 foot USB cable on amazon and it works but it is flaky and actually can cause the USB root controller on my motherboard to end up in a glitched nonfunctional state requiring a reboot!
These are commercially available, therefore it's absolutely possible. Designing it yourself would be a nice challenge
Is there any alternative IC for MI2099 because it is obsolete at most of the distributors
What would it take to create a 12 port usb hub? Would this require a board redesign or can we just add more usb ports? How about adding another host input and having this become a kvm for 2 pcs?
What if we get one of those USB hub and put four others behind it
Maybe a dumb question, but can someone kindly explain why the full board thickness is used in the calculation for controlled impedance and not the thickness between trace and its return plane (I.e. 1 x copper layer + 1 dielectric substrate).
Does this chip not require firmware? Or does it already come with built-in firmware?
Were the files uploaded anywhere? I’d like to make this USB-C, shrink it as small as it’ll go, and get it printed and assembled. I’d rather start from here, instead of trying to copy this and inevitably get it wrong ;)
Hi, Can you make a Bike (12V DC lead Acid Battery) Charging Circuit both USB-A and PD (for fast charging) for iPhone? Thanks.
Did you have to write the driver for this USB2514B IC? If yes how? What software.
I believe it is a single purpose chip that you don’t need to program. You just hook up the pins and power it. You can configure some settings via pull-up/pull-down resistors or you can attach an EEPROM to do the same thing.
Why don't you use one of the internal planes as a uniform 5V plane, instead of two GND's?
There is a video about that topic. For several si and emi reasons you don't want to have power planes on a 4 layer board. You could fill the top or the bottom signal layer with power to get a free HF capacitance but you do not want to switch reference plane (GND to 3V3!) if you need a via for your diff pair.
Why is filtering the 5 V rail required/recommend if it's going into a 3 V linear regulator? Aren't those filtering even better?
Ethernet phy design would be helpful. Those RJ45 connector with pins facing up/down is confusing
Definitely will be making a video on that!
Who else was taken off guard by the audio difference of the last part of the video. XD
jog on
Did you just say that you like Micro B????? Verry informative video, but that I can't get behind, it's the single worst connector apart from micro HDMI in my opinion. Been using only usb-c for the last 4 years in my designs.
Me too although I do have a soft spot for Mini-USB. Always reliable and as smooth as a cashmere codpiece in my experience (of both connectors and codpieces!).
Ok.
I've never thought of USB 2.0 as "high speed" 🤣
Guy is amazing but my only problem is that he shows what he has done, but not how to do it.
I just clicked thru the video... but did I get that right? Who the heck designs a USB-Hub chip that has to be fed 3.3Volts? USB itself is 5 Volts... So the controler chips supply is 3.3 but then again it has to output 5V on the USB? Wtf
The USB data signals are no more than 3.3v. The hub chipset doesn’t need 5v for anything.
Running it at 3.3v means it uses less power, among other benefits.
I have a question why the impedance profile is only limited to L2 and L3 and not all the layers?