USB Hub Powered From Mains

[engineer-labs]

After a fruitless Google search, I'm turning to you for advice.

I'm looking for a reference design or ideas on designing a 3-port usb hub that will run from the mains AC e.g. 90-240Vac.

Thanks in advance.

 

[FvM]

Reference designs are published by hub chip vendors. They usually rely on a 5V DC supply, so you need a small SMPS. Calculate 500 mA for each downstream port and about 300 mA for the hub, usually regulated down to 3.3V.

I have used SMSC/Microchip USB2514 4-port hub some time ago.

 

[engineer-labs]

Yeah. That was my 1st thought. But I was thinking someone may have designed a compact solution such as the ones in wall outlets where they also have USB ports. I wonder if those outlets have SMPS in them?

 

[engineer-labs]

Hmmm... I see. Let's see what others have to say.

Maybe they have designed such wall outlets.

 

[FvM]

I wonder if those outlets have SMPS in them?

I presume they have. Or you make a bus powered hub which can only supply low power devices.

"USB wall oulets" are usually USB chargers, they don't involve a hub, only a power supply. They surely need a 5V SMPS.

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You didn't tell the purpose of your design, USB charger or hub. In the latter case, what's the host computer?

 

[engineer-labs]

The client wanted to integrate a 6-outlet power strip with a USB hub. Need to clarify if he needs a hub or charger. Is it correct to say hubs are for data and power?

 

[FvM]

Is it correct to say hubs are for data and power?

Yes. There are however different current levels possible. You should make a complete specification. Also what kind of hub? USB2.0 high speed (480 Mbps) or USB 3.0 Gigabit rates?