Rugged USB card?

Something like this but for inside a PC would be nice:

something like this?

hard to see on the picture if theres any common mode chokes, but there's plenty of space for it

-Lasse

just hubs

Cheers

The USB3 card I got at Fry's has a power supply connector pin. How much more connected could you get? Unfortunately their server isn't answering.

I would do a search for a card that met the following:

My recollection is the card Fry's sold was a Syba. I tossed the box long ago. However the damn company sold two version of the card with identical part numbers. One was buggy. The one that worked had the NEC chip and the large molex connector. Fortunately I had a smartphone with me and google the card before buying it, and was able to get the right version.

So, put it inside your PC. Get a slot door with four USB ports on it.

Then replace that floppy, or floppy bay with one of these:

I have found that most of those are not properly grounded at the connectors. IOW the shield makes no contact to the metal. Then you get ESD and EMI issues (which is why I am looking).

In fact, we were able to make a card work but the rework is rather onerous.

Looks like they've got only low-capacitance TVS'es on there but hard to see.

Essentially this is like the Moxa box. Which is ok (and on order now) but ideally we'd like a PC card. Avoids having to mount yet another box into the system. And often those boxes are missing convenient mounting flanges so you end up reworking their box.

Yes, like the Moxa box, but these look a lot more expensive :-)

That one I don't understand. What for would I need a power supply connector? All we need is four USB connections for communication purposes, not to power anything.

So far all my searches yielded PC cards that had rather inferior grounding at the USB connectors and all were missing common mode chokes in the USB data lines. Those CM chokes plus proper grounding right into the chassis are rather important when it comes to susceptibility and ESD. Which is why custom designs always pass and COTS stuff nearly always fails when doing 8kV contact and things like that. If I could custom-design a PC card we'd be done, but time won't allow that on this project.

n it.

s.

somthing like this for the internal usb?

-Lasse

We have something like that. But:

a. No CM chokes. The only way to correct that is to find a ferrite bead of enough Al value but not so much as to mess up the end-of-packet signal, and then somehow roach those on there. Can be done but ugly rework. Now if anywone knows something like this with ferrites already on there I am all ears :-)

b. The L-bracket typically has no reliable connection to the individual USB shields and it also has no gasket to make sure it connects to the PC chassis all around.

How many do you need? It shouldn't be very hard to design a board.

Sure, but that's what we wanted to avoid :-)

We cannot possibly be the only ones who need level 4 ESD performance without resorting to external boxes.

Roll your own then.

What is the failure mode? Are your hubs being destroyed? Maybe you need an isolator instead.

Cheers

If we had the time I would suggest that. But we don't. We'll fix it, there I have no doubt. But I wanted to know if someone is aware of an elegant solution. IOW where some company builds a PCI-e card with four or more USB correctly and didn't screw it up.

We have data errors in the USB transmissions. That isn't supposed to happen in this system and is deemed a failure even though it recovers.

That would be the method of very last resort because those are north of $300 if you need four ports.

I guess you don't build PCs. Perfectly OK, just an observation.

The PCI/PCIE bus power connectors are crappy. What some devices finally ended up doing is adding Molex connectors so you can go directly to the power supply. This is common on high end graphics cards and usb cards If you think about, at half an amp a socket, there is a lot of juice going through the mobo contacts. These high end graphics cards are like CPUs these days in terms of power I wouldn't buy any USB card without the Molex connector on it.

I don't see how a common mode choke aids ESD.

Why not just ruggedize the part of the system where you have control?

One possible out would be to get a cable with an active USB driver in it. These are extension cables. You might luck out and find it has enough ESD to suit your needs.

Perhaps you can find a USB PCB socket with ESD protection built in, and then replace the sockets on the COTS device.

Or you build a cable that is a USB extender with some additional ESD protection.

A little capacitance goes a long way in improving ESD. If you don't need a full length USB cable, you could load the pins on the COTS card with additional capacitance.

Lastly, call a reputable chip maker like NEC and get their data on ESD. It may be a card with the NEC chip is all you need.

PCIE power is 12V so it is less than 1A for 4 usb ports

high end graphics cards need the extra connector because they need use several

-Lasse

In any event, the usb cards use the 4 pin Molex, presumably the 5V rail.