Simple USB hub design

Could any electronics guru on this newsgroup direct me to a not too complicated USB hub design ? I have been told that there are some that need firmware, while others do not. Any hints, suggestions would be greatly appreciated.

Reply to
dakupoto
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Design as in roll your own? Or design as in just buy one?

I'd suggest trolling the New Egg customer reviews, but I warn you, you won't find a hub without someone complaining it sucks.

In general, anything with a NEC chip is usually better than the pack.

Reply to
miso

And if it's a roll-your-own you're looking for, search for USB hub chips and see if the manufacturer has data sheets and app notes available.

I haven't tried this, so I don't know how well it'll work. It used to be that just about anything you wanted to do with an IC was supported with app notes and such, but these days if the market is large enough then you can't get any data without looking like you'll buy 100,000 units, or sign a non-disclosure agreement, or learn to read Chinese.

But you won't know until you look.

Chances are that the easiest designs involve slapping a USB hub chip down on a board with some connectors and a few discrete components -- you'll have to dig for yourself, though.

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Reply to
Tim Wescott

I have designed in several SMSC USB-ish chips in medium volume products and they work reasonably. Don't forget to add common mode chokes and transient suppressors!

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A device I choose randomly can even be bought in small quantities:

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Reply to
Nico Coesel

There is a need to read a lot of data from many USB flash drives. Would it be possible to plug several drives into a hub so several simultaneous USB 2.0 transfers would be combined into one USB 3.0 transfer to the root?

The 3.0 standard seems to allow for that; however I don't know if this actually supported by any hub or chipset. Rolling your own 2.0/3.0 hub using FPGA seems to be cumbersome.

Vladimir Vassilevsky DSP and Mixed Signal Designs

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Reply to
Vladimir Vassilevsky

I use the TUSB2046b from Texas Instruments. It uses a 6 MHz crystal and a few external components, and can be configured as a self-powered or hub-powered 4 port hub.

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About $3 in small quantities:

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The only problem I had initially, IIRC, was an unterminated RESET line or some other control pin. Otherwise it's just plug-n-play.

Paul

Reply to
P E Schoen

I have no idea whether that is supported or not. Besides that USB2.0 can already go up to 400Mb/s. I'm not sure if you would gain much speed. It depends largely on the USB flash drives and where the data needs to go.

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Reply to
Nico Coesel

I thought you might know as you actually design USB hubs.

All overheads included, useful transfer rate over USB 2.0 is only about

30 M/s. USB flash drives are near this limit at least for read speed. Several simultaneous transfers through USB 3.0 hub would definitely be big advantage.

Vladimir Vassilevsky DSP and Mixed Signal Designs

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Reply to
Vladimir Vassilevsky

When I look at the datasheets from an SMSC USB3.0 capable hub it seems the USB3.0 superspeed paths are seperated from the USB2.0 paths so a USB2.0 device will not be faster.

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So far I only used the USB2.0 ethernet and ethernet / USB hub combos from SMSC. The people responsible for the software in those projects however did extensive tests which show the chips are stable under load.

Doing a USB3.0 layout may not be trivial. Routing traces carrying

5Gbps on FR4 is doable but there are some pitfalls.

It seems it will take more work to get it going if you insist on using U@B2.0 flash drives. USB3.0 flash drives are already widely available.

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Reply to
Nico Coesel

Thanks for the feedback. This is basically what I was looking for, some sort of a reference design.

Reply to
dakupoto

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