Teardown: A Generic 7-Port USB 3.0 Hub That Wasn't

The trend of slapping two STT 4-port hubs together is so common, that even name-brand hubs for reputable brands are often this, including the back feed issues. I purchased hubs form a solar-named company, and one that has a similar name to a large US department store, and they were cascaded 4port, STT, ganged overcurrent and switching.

I've started buying PCBAs from Ali, where the vendor advertises the exact chip set in use. It's often cheaper than domestic options.

Listings for assembled hubs (whether ali or domestic) almost never include information about the hub's actual characteristics, unless you're looking at a 300+ hub sold to audiophiles.

I'd really like a source for a true 7p hub, with MTT, proper power, per-port overcurrent and power switching, but I can't seem to find one, especially since vendors tend to rev b2c products with no notice (one of the name-brand ones I bought had been downcosted shortly before I bought it).

Wow what an unexpectedly useful article! I have exactly this hub and wondered if I was imagining things. It absolutely has issues beyond that, for example I somehow managed to make a couple of ports unusable for micro-controller flashing even though they used to work just fine. For that price, it's an OK choice to low bandwidth stuff like periphery dongles and security keys, and the form-factor makes it easy to attach under desk or behind display. And buttons come in handy when you need to unpower a dev board. Anyone can recommend a similar shaped proper USB 3 hub off Ali?

My first thought whenever I come across such a badly-engineered no-name device is "oh great, another bad reference design which will poison the pool of all the available devices out there"

It helps a bit to spot and avoid that exact exterior design, but often those devices are designed to reuse the same mold as more-expensive ones and/or keep changing the design based on the purchasing customer.

So you end up on AliExpress looking at 5 identical hubs, but the cheapest one may have a different PCB inside.

Or you look at 5 different hubs, with all of them having the same PCB inside...

It's a classic scam. It is a 3.0 USB 7-Port Hub, not a 7-port USB 3.0 Hub. The number 3.0 is the model number of the hub, not the protocol.

Whats always annoying is by using nested 4-port hub chips inside a hub with more than 4 ports you get very easily to the max nested depth limit (5). I have a monitor kvm switch that is also an usb hub. It itself only has two ports. Two usb hubs (that are internally nested) are plugged into those ports that I have at the back of my desk where all the HID are plugged in, but I also have a usb hub on the front of my desk so I can easily hotplugmy joysticks, yubikeys and usb flash drives.

Apparently that use case is very complicated with USB even in modern times :(

The linked article on the same blog on building a tower of optical drives is also quite interesting: https://goughlui.com/2026/03/15/project-building-an-optical-...

> This means a connected external power supply will backfeed the computer and that could be a recipe for damage to the port or the computer and is something we had known about causing issues over 20 years ago, yet we’ve still got designs with this issue today.

On the other hand it's useful for space constrained embedded projects. I got a small outdoor enclosure for a Pi Zero, to which two RTL-SDR sticks are attached - too much to supply via the Pi's USB-OTG power rail alone. With the Adafruit microUSB OTG hub [1], I now only have one power supply going into the hub that backfeeds the Pi Zero... one cable less.

[1] https://www.amazon.de/dp/B0DBMXCTRG