High-speed USB isolator - Page 1
Forum section: electronics / general

author: cybergibbons
author_rank: Frequent Contributor
timestamp: July 24, 2011, 01:04:29 pm
content: I've had a few mishaps now where I have blown up a USB port on a desktop machine and written off a monitor with a built in USB hub before now. I have a lot of bare circuit boards with USB interfaces and a number of pieces of test equipment (Bus Pirate, Open Bench Logic Sniffer, Saleae Logic, Scope, RS232 adapter, FTDI cable, GoodFET...) so it is only a matter of time before something untoward goes down a USB cable.There are USB isolators available, but they are only full speed (12Mbps):http://www.olimex.com/dev/usb-iso.htmlhttp://www.bb-europe.com/product_family.asp?FamilyId=651&Trail=168&TrailType=MainAnd there are also hubs available, but all seem to be full speed, not high speed.I'm not sure how much protection I really need or want. Worst case really is going to be 60V at 3A from my bench power supply.Any ideas?

author: ejeffrey
author_rank: Super Contributor
timestamp: July 24, 2011, 01:26:19 pm
content: I have seen high speed isolators but they are pretty expensive. They might end up being more expensive than the equipment you want to protect...Since you basically just want to protect equipment, not provide a safety isolation barrier you might get away with just using a cheap hub. It won't protect against everything, but it might die first and save whatever it is connected to. Since most USB hubs are powered via an isolated DC-DC converter, you should run a separate grounding wire to provide a ground path for any overvoltage. Just get an extra USB cable, cut off the 'A' end, and solder a grounding wire to the shield. Then plug it into your hub.You could also roll your own passive surge suppressor device. A usb B to A pass-through box with TVS diodes on each wire should do the trick.

author: onemilimeter
author_rank: Frequent Contributor
timestamp: July 25, 2011, 02:29:23 pm
content: May be those product uses this IC:http://www.analog.com/en/interface/digital-isolators/adum3160/products/product.htmlExamples of high-speed USB isolator in the market?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: July 25, 2011, 03:56:20 pm
content: I found this - doubtless very expensive...http://www.baaske.net/usb2_galvanisch_trennen.html?&L=1The problem is there aren't many isolation devices that will run at the 480mbits/sec full speed. You're probably limited to either multiple isolators in a parallel bus, or laser based fibre-optics as used in the above product. I wonder if you could do something with gigabit ethernet magnetics.You then have some very high speed logic to deal with as well, and the market is small, so it's never going to be cheap.However if all you want is protection it should't be hard to make a pretty bulletproof protection circuit - low-capacitance TVSs, and maybe polyfuses to protect the TVSs against sustained DC.

author: ejeffrey
author_rank: Super Contributor
timestamp: July 25, 2011, 04:07:38 pm
content: I just looked at the ones we have in our lab. I thought they were high-speed compatible, but they are only full/low speed.I suspect one problem here is that the signaling voltages and line termination are different between 1.5/12 Mbit and 480 Mbit, and uses a variety of pull-up/pull-down resistor switching tricks to negotiate the speed in a backward compatible way. Making an isolator properly handle the negotiation on both ends for all possible configurations while being transparent to the host is probably more trouble than it is worth. Opto-isolation is most common in industrial environments, and the most common devices are simple serial devices for which even 1.5 Mbit is more than sufficient.

author: cybergibbons
author_rank: Frequent Contributor
timestamp: July 25, 2011, 05:24:59 pm
content: As you say, the tricks used to get backwards compatibility along with such high speeds may be why they are so rare. The cheapest option is probably just to have a computer that I accept is going to get damaged and not have any data on it that I really need!The full speed isolator will probably do for some equipment - I think a lot of things report high speed but run at much reduced speed. The Saleae Logic is probably the only thing that needs to run at high speeds.

author: Time
author_rank: Frequent Contributor
timestamp: July 25, 2011, 06:20:06 pm
content: Look into the Analog Device I-couple technology. They make some cheap and good high speed isolators based around aircore pulse transformers.http://www.analog.com/en/interface/digital-isolators/products/index.html#Standard_Isolatorshttp://www.newark.com/analog-devices/adum1100arz/ic-digital-isolator-18ns-soic-8/dp/19M0749Not sure if that helps or not. I am not familiar with USB so I am not sure if something like this would work.

author: onemilimeter
author_rank: Frequent Contributor
timestamp: July 25, 2011, 06:28:28 pm
content: Quote from: Time on July 25, 2011, 06:20:06 pmUsually the isolator is unidirectional...

author: Time
author_rank: Frequent Contributor
timestamp: July 25, 2011, 06:33:29 pm
content: Oh just noticed your post. Sorry about that.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: August 10, 2012, 10:34:02 pm
content: http://www.icron.com/make some hi-speed USB over cat5 and fibre interfaces. Not clear if the cat5 ones provide isolation.

author: jamesp15
author_rank: Regular Contributor
timestamp: August 10, 2012, 11:09:43 pm
content: If its a desktop PC: What about using cheap PCI/PCIexpress USB adapters, if one blows you don't lose a motherboard.Quite a few on ebay under $10 US.

author: David_AVD
author_rank: Super Contributor
timestamp: August 10, 2012, 11:10:13 pm
content: Another danger in any connection to a PC (not just USB) is large currents flowing in the ground wire.Using a PCI USB card on the PC and making a little box to put a 500mA fuse in series with all 4 wires would at least limit the damage.

author: T4P
author_rank: Super Contributor
timestamp: August 11, 2012, 04:08:15 am
content: Best way is to use a powered USB hub, at least the motherboard ground wires from PCI doesn't go boom or the Southbridgeyour computer might have polyfuses but that's not good of a idea

author: hans
author_rank: Super Contributor
timestamp: August 12, 2012, 06:31:20 pm
content: At home I always use a $10 Sweex (I believe this is a local dutch el-cheapo brand) USB hub. Works fine, own power brick so it's (hopefully) not drawing any power from the PC to power the devices. This does have the consequence not being power limited I think, because I have blown 2A MOSFETs on my PICKIT2 before (bloody PICKIT software hang and accidently shorted the power output, smoke)If you want to 'isolate' a single USB port, you may find it convenient getting an old laptop and use that. This of course brings issues if you have 2 USB devices, because USB on the laptop still has the same ground. And working on it from the 'workstation' isn't convenient.This also stresses the disadvantage of high-speed USB devices on USB. Like a RS-232, bus pirate and low-bandwidth thing is probably something you can run on a hub plus 12mbit isolator. A scope or logic analyzer not. Laptop for 'debugging' via scope and such only? Futhermore, how big are the odds you need your logic and scope simultaneously? (scope: signal quality, logic: protocol debugging)I don't think a PCI-e device will work though like james suggests. There is a chance they probably don't have any fuse and will probably blow the motherboard anyway. The device is powered from the motherboard after all.I see on many modern motherboards polyfuses now. I paid close detail on when purchasing my last PC whether they contained them, but I actually couldn't find any motherboard without. Though, I did spent 170$ or so on my MB, so I guess it *should* have some protection.What exactly have you blown? I also played with projects at internship and college with USB. This is ofcourse on a laptop (Samsung R510 AS02) and not in my own hobby space. I shorted out the +5V to pretty much anything whilst completely messing up (and messing up the fixes!) the pin-out of an USB B connector, and the only damage I did was to my projects. All 3 ports still work.That experience gave me so much trust in this laptop I'm not afraid of blowing it up.. At internship I didn't have the right cable for an industrial USB boxed header connector (like onboard of a MB). So I disassembled one and directly connected the crimps on the headers, with no connector.. A fellow intern, which is a bit more sloppy with everything, was a bit nervous seeing that. He said that if he would do that, he would always short something out and kill it. Worked great for the few things I had to (re)configure over USB

author: NiHaoMike
author_rank: Super Contributor
timestamp: August 12, 2012, 07:02:56 pm
content: I have an IOGear wireless USB hub that I got on sale for $20 or so. Range isn't too good, but it works perfectly for isolation.The difficult part of isolating USB 2 is because the data lines are bidirectional. The interesting part is that isolating USB 3 would actually be quite easy for anyone experienced in high frequency design, because the two USB 3 pairs are unidirectional. It might be as easy as wiring the lines to a pair of fiber transceivers. It might also be possible to use transformers since USB 3 is AC coupled, but I'll have to check the frequency range.If possible, isolate the connection where it's easy to do so.

author: Icchan
author_rank: Regular Contributor
timestamp: September 19, 2015, 12:49:27 pm
content: I've come up against this issue too.I was planning to use an high spec USB audio interface for signal analyzing and spectrum analyzing, and I'm worried about the USB power quality messing up the specs for the interface. Not to mention to prevent me blowing stuff up.Might not be an issue if I research and test it further, but it's really hard to find anything below 300€ for isolating USB 2.0 high speed connection.Surprising since I wouldn't think it would be that hard to do :/

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 19, 2015, 03:54:41 pm
content: Quote from: Icchan on September 19, 2015, 12:49:27 pmConvert the USB to I2S or S/PDIF and then isolation is easy or trivial.

author: C
author_rank: Super Contributor
timestamp: September 19, 2015, 05:58:54 pm
content: USB-3Could be wrong, but my quick read of USB3 is that it is USB2They just added two unidirectional differential pairs. and extra packet types to control the two channels.USB-3 = USB2 + two unidirectional differential pairs.C

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 19, 2015, 07:24:28 pm
content: Quote from: C on September 19, 2015, 05:58:54 pmUSB 3.0 will work with the USB 2.0 pair disconnected. Not sure about USB 3.1.

author: C
author_rank: Super Contributor
timestamp: September 19, 2015, 10:26:16 pm
content: Thank you NiHaoMikeI did did not see that, nice to know.Did you see any difference with 2.0 pair disconnected?C

author: Howardlong
author_rank: Super Contributor
timestamp: September 20, 2015, 04:20:37 pm
content: Two other options...I have a Belkin (gag) Network USB Hub F5L009 v2 from a few years back. I am sure other makes are available. This is not just a physical layer CAT 5 thingy, it tunnels USB over IP. This will be isolated as it'll go over Ethernet magnetics.The other option might be the almost forgotten wireless USB technology based on UWB. I have a Q-Waves USB to HDMI adapter from about five or six years ago, they also have a wireless USB to USB adapter (http://www.amazon.co.uk/Q-Waves-Wireless-USB-Data-Kit/dp/B002T9VBVM/ref=cm_cr_pr_product_top?ie=UTF8) currently deeply discounted to £15. There might be a reason for that though, not sure what the driver situation is for these devices.

author: Stonent
author_rank: Super Contributor
timestamp: September 20, 2015, 05:50:47 pm
content: Quote from: mikeselectricstuff on August 10, 2012, 10:34:02 pmWe've used the Icron fiber devices where I work. I would recommend using an add-on wall-wart rather than the USB port to power the device as we've had them cut out when the load gets too much.Since the fiber ones use standard multi-mode SFP modules, they are easily serviceable. I would be reasonably sure that the cat5 version uses the same mag jacks as you would normally use for Ethernet.I've used some of these before:http://trinetusa.com/products/usb-2-plug-play-utp-extender-1to1/It uses standard Ethernet to transmit the data, the computer end of the device is just a USB to Ethernet device and will function as so if you load the chipset manufacturer's drivers.To use the USB over Ethernet functionality, you need to install the software that comes with it that creates some kind of tunnel. You can even sniff the traffic using a packet sniffer and it's just all TCP/IP traffic.The PC side uses an ASIX USB to Ethernet chipset and uses an Ethernet mag jack, so it would give you whatever isolation level that a mag jack can do.

author: wreeve
author_rank: Unknown
timestamp: September 20, 2015, 06:29:32 pm
content: I've used the USB 2.0 Isolator fromwww.electronics-shop.dka few times in lab environments where the chassis connections of USB connectors can corrode causing GND loops if you are not careful! USB seems to hate GND loops!

author: wraper
author_rank: Unknown
timestamp: September 20, 2015, 06:33:13 pm
content: Quote from: wreeve on September 20, 2015, 06:29:32 pmBut it's full speed only = 12 Mbps

author: Stonent
author_rank: Super Contributor
timestamp: September 20, 2015, 09:03:49 pm
content: Quote from: wraper on September 20, 2015, 06:33:13 pmThe ones I mentioned go all the way. They are sold as USB Extenders which use CAT5E cable as the transmission media, but they use ethernet Mag Jacks and are isolated.http://www.trinetusa.com/images/spec_sheets/electronic/R042-EXT-C5E.pdfQuote

author: free_electron
author_rank: Super Contributor
timestamp: September 20, 2015, 09:11:40 pm
content: The problem with isolators is that they inject roundtrip delay because they need buffering. for 480mb/s the delay is just too long.the solution is to use a simple cheap, self powered, hub inbetween. if you fry anything it'll be the hub.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 20, 2015, 09:31:33 pm
content: Quote from: free_electron on September 20, 2015, 09:11:40 pmUnless you get a few tens of amps flowing through the ground return...Or the "frying" event is sufficient to arc between sides inside the hub chip.

author: nctnico
author_rank: Super Contributor
timestamp: September 20, 2015, 09:44:48 pm
content: I think the USB over ethernet is the simplest solution. Ethernet is isolated by default (around 1kV-ish) and if you need more isolation then you can switch to fibre.

author: jcbottorff
author_rank: Newbie
timestamp: February 03, 2017, 10:06:31 am
content: Just an update on available USB isolation products. This sitehttp://hifimediy.com/Accessories/high-speed-usb-isolator-480Mbpssays they have a high speed USB isolator (auto selects 1/12/480 mbps) for about $80. There is also a CoolGear high speed USB isolator for about $190 athttps://www.amazon.com/dp/B01E68ME7SThere also are reports of a long Corning USB 3.0 5 Gbps optical cable for $100,https://www.amazon.com/dp/B00JOJRF6KIt doesn't transmit power, so you need an isolated powered hub.I just bought, and am about to return, a $40 isolator which claimed low and full speed, but reality was it only supports full speed. It's the single port version ofhttps://www.aliexpress.com/item/1-to-4-Usb-isolator-digital-isolation-usb-2-0-hub-for-audio-signal-power-supply/32325766995.htmlfrom an Amazon seller. The aliexpress website spells out full speed only, the Amazon vendor didn't. Adafruit has a bare isolator, with a low/full speed switch for $35https://www.adafruit.com/product/2107

author: David Hess
author_rank: Super Contributor
timestamp: February 03, 2017, 09:22:45 pm
content: Quote from: jamesp15 on August 10, 2012, 11:09:43 pmDoing that is better than nothing but still requires luck to prevent system damage and does nothing to prevent a destructive ground loop. USB was not designed to connect instrumentation or operate across AC power domains.The big problem with USB isolation is that it is half duplex effectively requiring an isolation barrier to also operate as a hub to decode what is going on. This makes even 12Mb/s Full Speed isolation difficult. If you want 480Mb/s USB 2.0, then you will have to pay and other solutions become economical. Use Ethernet if you can.

author: nidlaX
author_rank: Frequent Contributor
timestamp: February 03, 2017, 09:33:00 pm
content: Quote from: jcbottorff on February 03, 2017, 10:06:31 amI can vouch for hifimediy as a vendor (their USB DAC is quite good), but I have not used their isolator.On another note, have you ever looked at the Corning USB 3.Optical cables? It looks like a very nice solution using optical transceivers / fiber as a bridge between USB A endpoints. These are good for up to 5 Gbps!Product page:https://www.corning.com/optical-cables-by-corning/worldwide/en/products/usb-optical-cables.htmlBH Photo for a 33' cable:https://www.bhphotovideo.com/c/product/1057862-REG/optical_cables_by_corning_aoc_acs2cva010m20_type_a_plug_to.htmlAlso, here's an HV isolated USB 3.0 hub for reference:http://buy.advantech.com/USB-4630-AE-USB-4630-AE/USB-4630-AE/model-USB-4630-AE.htmI must say, a lot of great USB isolation options have emerged in the last couple of years.

author: Mark
author_rank: Frequent Contributor
timestamp: February 03, 2017, 09:43:27 pm
content: Quote from: jcbottorff on February 03, 2017, 10:06:31 amI just ordered one, thanks! These definitely come in handy when trying to probe isolated ADC channels using a USB 'scope like the Analog Discovery.

author: Lord of nothing
author_rank: Super Contributor
timestamp: February 07, 2017, 12:50:08 am
content: http://www.delock.de/produkt/62588/pdf.html?sprache=en

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: February 07, 2017, 08:13:04 am
content: Quote from: Lord of nothing on February 07, 2017, 12:50:08 amThat's full speed only, not high speed

author: f5r5e5d
author_rank: Frequent Contributor
timestamp: February 07, 2017, 08:24:36 am
content: https://www.amazon.com/dp/B00JOJRF6Ksounds like it isn't isolated, runs copper the length of the cable to power the optos

author: MrW0lf
author_rank: Frequent Contributor
timestamp: April 14, 2017, 08:46:56 am
content: Due torequest in other thread:Olimex USB-ISOis 12Mbps indeed, if want go higher found some other options, but do not have them:https://hifimediy.com/hifimediy/high-speed-usb-isolator-480Mbpshttp://www.coolgear.com/product/usb-isolator-high-speedShould anyone get/have these or similar please report back. I'm very interested in 480Mbps option.But back to Olimex, ok, did cut my puppy open..andADUM4160it is!

author: voltsandjolts
author_rank: Unknown
timestamp: April 14, 2017, 10:27:50 am
content: Not cheap (GBP99) but this works for me:https://www.lindy.co.uk/usb-firewire-c4/100m-cat-5-usb-2-0-extender-lite-p7368

author: Lord of nothing
author_rank: Super Contributor
timestamp: April 14, 2017, 10:29:12 am
content: is an extender not isolator?!

author: voltsandjolts
author_rank: Unknown
timestamp: April 14, 2017, 10:39:57 am
content: Quote from: Lord of nothing on April 14, 2017, 10:29:12 amIt's both!Uses ethernet isolation magnetics.Edit:Uses "Jiangsu Qinheng Co., Ltd"(!!!?) CH317http://www.wch.cn/product/CH317.html+ Realtek RTL8211E to drive the magjack

author: LaurentR
author_rank: Frequent Contributor
timestamp: April 29, 2017, 11:41:26 pm
content: Just got my HifiMeDIY USB2 isolator.https://hifimediy.com/high-speed-usb-isolator-480Mbps$89, shipped from Vava'u, TongaIt is based on a Silanna ICE USBB chip for data lines and an isolated 5V-5V DC-DC converter for power.Silanna press release:http://www.prweb.com/releases/2015/10/prweb12995871.htmAnd yes, soldering quality is "moderate".I have only tested it with my old Saleae Logic 16 and it does the job at full acquisition speed (which is what I bought it for).

author: splin
author_rank: Frequent Contributor
timestamp: April 30, 2017, 02:58:52 am
content: Quote from: Stonent on September 20, 2015, 09:03:49 pm404 Not Found? (Same goes for your previous link).I guess you mean this:http://www.trinetusa.com/product_description.php?PNo=173Seems it could be a good solution at $88 - in the US. Probably $888 in the UK with shipping, duty, highway robbery handling fees, VAT on all the above etc, etc.What a horrible and uninformative website!

author: nidlaX
author_rank: Frequent Contributor
timestamp: April 30, 2017, 04:56:36 am
content: Quote from: blueskull on April 30, 2017, 03:54:54 amI did!

author: nidlaX
author_rank: Frequent Contributor
timestamp: April 30, 2017, 05:22:29 am
content: Quote from: blueskull on April 30, 2017, 05:11:11 amNotice me senpai!

author: eliocor
author_rank: Unknown
timestamp: April 30, 2017, 06:53:47 am
content: It seems to me that the Corning one is not a real insulator...Power supply come from the optical cable (2 copper wires) and nowhere in the datasheet is reported the insulation value.As blueskull wrote, you have to modify the cable to render it an insulator USB cable.

author: electronic_eel
author_rank: Regular Contributor
timestamp: September 09, 2019, 11:08:11 pm
content: I know this thread is a bit older, but it still comes up when you search for technical details of isolating USB.I found one more isolation product: A USB 3.1 Gen 1 (SS with 5 GBit) Hub with isolation.I found it sold under these names:coolgear CG-U31iS4PH,https://www.coolgear.com/product/4-port-usb-3-gen1-isolated-hub-15kv-esd-surge-protectionExsys EX-1182VIS,https://www.exsys.de/index.php?page=product&info=2062The OEM developing & manufacturing these is most probably:Comwise Tech MG-14346IS,http://35.222.228.198/usb-hubs/When opening it, you see a quite interesting concept: isolating USB 2 (from Low Speed to High Speed / 480 MBit) is done differently than USB 3 Superspeed. USB 2 isolation is done with the Silanna ICE08USBC, similar as in the HifiMeDIY described above. USB 3 SS is isolated with ceramic coupling capacitors.There is a regular GL3522 hub IC at the input. One of it's downstream ports goes to the isolation barrier, splitted by protocol as described above. This is most probably being done to buffer the USB 3 SS signals, to create a clean and known signal across the coupling capacitors. On the other side of the isolation barrier is another GL3522 hub, which connects the 4 downstream ports.There is a Minmax MA01-05S05HI DC/DC voltage regulator on board. It provides 200 mA, just enough to power the hub itself, it is not designed for onnecting bus powered peripherals. You can disconnect it with the jumper on the pcb. The DC/DC isolates 5.2 kV for 60 seconds. That translates to about 400 VDC permanent isolation, which is more than is offered on the data path, see below.For bus powered peripherals you are supposed to connect an external 5 V power supply through a 5.5 / 2.1 mm barrel connector.Finding details about the Silanna ICE08USBC is a bit difficult, as Silanna doesn't publish any datasheets. The best I could find is this presentation about their portfolio:http://spacewire.esa.int/WG/SpaceWire/SpW-WG-Mtg17-Proceedings/Documents/Session 7 - SpaceWire Link Isolation (G.Baterina).pdfOn page 7 you can see how the IC is internally constructed. It seems to use capacitive coupling internally. So all claims about "optical isolation" you see in the Exsys datasheet are misguided.On page 8 they claim isolation for 2.5 kVrms. Comwise Tech claims 3 kVrms in their datasheet. It could be that Silanna improved the isolation in the ICE08USBC, the presentation is from 2011 and they show the SIL11USBx which is probably a predecessor of the ICE08USBC. It could also be that Comwise Tech confused DC and AC rms.Also they clearly state "Working voltage >100V". That means the 2.5 kVrms are just specified for a short period, usually 60 seconds. After that the isolation slowly begins to break down. The working voltage is what they consider safe for permanent usage. 100 V permanent matches what is commonly specified for DC/DC converters rated 2.5 kVrms @ 60 s.The ceramic capacitors crossing the isolation barrier are 1812 size with 2 mm height. I measured them at about 1 nF. Several manufacturers offer such caps in X7R rated for 3 kVDC. I didn't find any for higher voltages in 2 mm height. So one can assume that they are rated for 3 kVDC. In the Datasheets they allowed for short-term overload to 120%, so no 3 kVrms. Also they warned not to use them for AC applications with continuously changing polarity.The problem with capacitive coupling is that if the downstream side is floated to AC, a current starts to flow across the isolation barrier. With the voltages safe for permanent usage and a sinusoidial 50 Hz the current is in the µA range and doesn't matter much. But when using rectangular AC this can quickly become an issue and for example destroy the hub ICs because the data lines go outside their allowed common mode voltage.There are no bulk capacitors anywhere on the pcb. The USB spec requires a minimum of 120 µF per downstream port, connected to the same net as the socket, after any protection measures. This is clearly missing. When plugging in a new device or when a device creates a current spike, the power for the 3 other ports or the hub IC can droop. This could be fixed by modding the board and soldering some polymer caps in the right places.It seems like there are ESD protection ICs, the MSOP-8s labeled "118 6yUHG". I couldn't find a product name or datasheet with this marking. The SOT23-5 near the downstream ports are most probably short circuit protection ICs.I did some USB data transfer measurements: transfer with USB 2 HS was a little bit slower (336 MBit/s) than directly connected to the PC (352 MBit/s). But this is very similar to what I measure on all my other hubs, so probably more related to having a hub in between at all than this specific hub. I couldn't measure a difference in latency, as USB latency tends to be hard to measure precisely. These measurements were done with the "benchmark" applet of Glasgow revC1 (Cypress FX2 + FPGA)https://github.com/GlasgowEmbedded/Glasgow.I do not have a device to constantly saturate a USB 3 SS link. So for USB 3 SS I just did stability and data integrity tests, as I've also had USB 3 hubs which had connection problems under load. I wrote and read back 1 TB without disconnect or a data error.Final Verdict:Good:- Isolated USB up to 5 GBit/s, no shortfalls with USB LS, FS and HS- Ready-to-buy solution- Convenient to use as it directly provides 4 ports and a power plug- Solid construction- ESD protectionBad:- Permanent voltage allowed across the isolation just about 100 VDC, so not suitable for connecting USB instruments floating on mains levels- Capacitive coupling precludes some usage cases with AC- No bulk capacitance on downstream ports as mandated by USB spec- Costs about 200 EUR

author: electronic_eel
author_rank: Regular Contributor
timestamp: September 09, 2019, 11:10:09 pm
content: One more pcb photo which didn't fit in the previous post.Also a copy of the Silanna pdf presentation linked above, just in case the they remove it.

author: ajb
author_rank: Super Contributor
timestamp: September 10, 2019, 08:28:18 pm
content: For an interesting but waaaaaaaay overkill solution, PCIE over fiber extenders exist:https://adnacom.com/pcie/Totally ridiculous for USB isolation, but could be a good solution if you needed to isolate some sort of PCIE expansion card interface.

author: electronic_eel
author_rank: Regular Contributor
timestamp: September 10, 2019, 09:33:08 pm
content: Quote from: ajb on September 10, 2019, 08:28:18 pmIt is indeed way overkill for a USB solution, but I think the pricing of $575USD for the Adnaco-S1B is quite reasonable for what they do and how custom this solution is. When seeing the pictures on the overview page, I expected prices in the middle 4 digit region.

author: electronic_eel
author_rank: Regular Contributor
timestamp: September 10, 2019, 09:41:10 pm
content: To complete my evaluation of USB 3 capable isolation solutions, I also bought the 10 m version of the aforementioned Corning optical cable.As mentioned above, this is not intended as isolation solution, but as a USB 3 SS (5 GBit/s) range extender up to 50 m. The cable contains two optical fibers and 2 thin copper wires for power supply. You have to open the cable and cut the copper wires to get isolation.The cable is overmolded with a quite rigid rubbery plastic, probably some kind of polyurethane. Opening this to get at the power wires without destroying the optical fibres isn't easy. I tried different methods and found that using a sharp medical scalpel and scraping off small flakes of the plastic works best. Once you hit the wires you can carefully try to pry them off the plastic that encloses them. The optical fibres are surrounded by yellow protection fibres. Try to disturbe them as little as possible.Once you freed the wires on a length of about 1 cm, cut the wires at the host side. Solder wires leading to a power connector to the device side. Isolate the joints with heat shrink tube. The plastic provided mechanical support and protection for the fibres. This is now mostly gone on the centimeter we opened. We have to add back something similar to make sure the fibres don't break. I used thick self sealing tape and wound it around the "wound" and my new power wires. I managed to keep my wire working, but when seeing the yellow protection around the fibres it felt like a close call. There is definitively a risk to destroy the cable.The blue wire carries +15 V, the turquoise one ground. It seems they use a stepup to increase the voltage to 15 V, probably to minimize losses over the full 50 m they offer. But this is just for powering the device end of the cable, it is not intended for bus powered devices. When plugging in the cable, the current draw of the device end is a little bit under 100 mA at 15 V. This quickly drops to about 30 mA when idle.So for a bus powered device you also need a hub, power supply for the hub and 15 V for the device end of the cable.The host and device ends of the cable look like they are glued together and opening will break them. As my cable survived the isolation surgery, I didn't want to risk that.The cable presents itself on the USB as two Hitachi hubs (one USB 3 and one USB 2) and a "Corning Optical USB V1.1" device, see attached lsusb output. Devices attached to the cable show up below the respective hub. I successfully tested devices with USB Fullspeed (12 MBit), Highspeed (480 MBit) and Superspeed (5 GBit). I also tried to plug it into a USB 2 socket on my pc and then the devices were just using up to 480 MBit connections. This leads me to believe that they implemented this properly with a distinction between USB 2 and 3 and not with a hack like a 2-to-3 transaction translator.Transmission speeds were very similar to what I got with the Exsys hub presented above. Also the transmission with USB 3 SS was stable for 1 TB.I don't know why they implemented the cable this way. It seems they were completely focused, like wearing blinkers, on a small and thin consumer solution to extend USB 3. Why didn't they split this into two small boxes that are connected with regular OM3 fibre over LC connectors, the device side powered with a small 5 V wall wart? Then you don't need different products for different lengths, the user would just buy matching pre-made fibre patch cables which are common. Isolation would have been covered too and you could also use it with a fibre installation in a office building.Final Verdict:Good:- Isolated USB up to 5 GBit/s, no shortfalls with USB LS, FS and HS- Fibre optics provide stable and safe isolation for very high voltages, permanent mains voltage is no problem- Very low capacitive coupling allows to float the device side to ACBad:- No ready-to-buy isolation, wire surgery necessary for isolation- Risk of damaging the fibres- Limited mechanical stability where the wires were cut- Costs about 150 EUR- Hub, power for the hub and 15 V for the device end of the cable not included

author: MT
author_rank: Super Contributor
timestamp: September 10, 2019, 09:54:02 pm
content: So can a debugger like STM32 Nucleo/Disco be on a WIFI router or will the router not recognize the device?I do not have WIFI router.

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 10, 2019, 11:52:10 pm
content: Now that the Raspberry Pi 4 has native 1G Ethernet, has anyone benchmarked it as a USB/IP bridge?

author: Lord of nothing
author_rank: Super Contributor
timestamp: September 11, 2019, 12:09:01 am
content: I use there USB to Fiber Kit:http://www.studiofibersystem.com/The legal import costed me a Ton of Fees () but the work.I hope the will work with my ESXi to. I also have an Icron Set but the first one was broken (maybe a cold Solder Joint) now I got an replacement I have to mount.Well an "ordinary" Fiber Cable is the best thing because the length doesnt realy matter in a Home use. 10m, 20m, 30m,... 100m isnt any problem. And when someone destroy the Cable a new one dont cost me that much to replace.I would never buy such Corning for SDR Stuff only if the USB Connection dont matter.

author: electronic_eel
author_rank: Regular Contributor
timestamp: September 11, 2019, 07:11:40 am
content: Quote from: Lord of nothing on September 11, 2019, 12:09:01 amInteresting, thanks for sharing the link.Which of exact product do you have?Did you test if USB 3 Superspeed (5 GBit) and also USB 2 Highspeed (480 MBit) transfers work?

author: Lord of nothing
author_rank: Super Contributor
timestamp: September 11, 2019, 10:15:42 am
content: QuoteI check if the SDR work. And one SDR work now. If I find a good Signal Splitter I will connect more.The should work do to the Claim of the Seller.QuoteThe seller told me my Product isnt on the Market right now.Contact smugzhang@gmail.com and say you want the same as mine: PI No.: JM-USB-201905161