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Any short-circuit protection for USB port on m/board?

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nicleo

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usb short circuit

As USB interface carries power (VBUS, 500mA), is there any short-circuit protection (circuit) on motherboard?
 

House_Cat

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usb short circuit protection

If the motherboard complies with USB specifications, it is supposed to limit current to 5amps maximum for overload. The limit may be designed into the power supply, or be a fuse, a circuit, a resetable device, etc. on the board.
 

Bluechem

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short circuit usb port

nicleo said:
As USB interface carries power (VBUS, 500mA), is there any short-circuit protection (circuit) on motherboard?
I think you can't rely on that and you shouldn't. every manufacturer has its own way. what you can rely on is usb protocol standard and hardware specifications required by usb protocol.in that way even if one motherboard couldn't supply the maximum current, it is not your product fault. you can tell your customer "our products comply with all standards, it is your computer that is non-standard" :wink:
 

nicleo

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usb overload protection

House_Cat said:
If the motherboard complies with USB specifications, it is supposed to limit current to 5amps maximum for overload. The limit may be designed into the power supply, or be a fuse, a circuit, a resetable device, etc. on the board.
Wowww... 5 amps (x10 times of 500mA), that's a lot. No wonder the Intel ICH5 chipset on my m/board burnt.

Pls refer to the figure below. The connectors shown are connectors at both end of the USB cable (used to connect digital camera to PC) and connector on digital camera. If the connector on the cable at digital camera side is not plugged 'deep enough' into its female connector on digital camera, do you think, when the digital camera is powered on (there is a POWER button to enable), would it cause short-circuit and hence damage the Intel !CH5 chipset on the m/board? Pls read this link for details on how I operated/setup the file transfer between the digital camera and PC via USB interface before my m/board burnt.

I could not post the purpose of asking this question here again, but pls help to clear my doubts as stated in
 

movingbait

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short-circuit usb

you can check with

https://www.ftdichip.com/Files/usbview.zip

a sample output
************************
Number of Ports: 4
Power switching: Individual
Compound device: No
Over-current Protection: Individual

************************
No Over-current Protection (Bus Power Only)
***************************
 

nicleo

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short circuit protection usb

I ran the program in my OLD PC. The results shown in the figure. What does "No Over-current Protection (Bus Power Only)"? Does it mean that Intel(r) 82801AA USB Universal Host Controller do not have such protection?
 

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short circuit motherboard

Nicleo -

First let me say that I have two Olympus cameras, and I follow the same connection procedure that you do. I have never had a problem on any of the three computers to which I regularly connect. I've been using my Olympus C2020 for about 4-5 years, and my C8080 for about a year.

It is unlikely that you have a problem because the connector wasn't pushed in far enough. It IS possible that you have a bad cable with some sliver of metal where it shouldn't be. It is also possible that you had a bad chip that just happened to blow when you put a load on it - a coincidence. Finally, it is possible you have a defect in the camera itself - this should have smoked the camera as well as you MB since it is unlikely it could handle as much current as the MB.

Next - the Micr0s0ft USBVIEW utility that you are using is intended only for XP systems running SP1 or above. The information you get from other operating systems may be incomplete or erroneous because the software flags won't be right. That said - yes, the message means that the port is directly connected to the +5V bus without protection. It is one of the three types for USB devices (i.e. type 1 - Low power, bus powered (100 mA), type 2 - High power, bus powered (500 mA), and type 3 - Self powered, but may use bus power when in power save mode).
 

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usb short circuit damage

I have seen on the other PC that is youngher than this and every USB port is protected with a SMD polyswitch on the mother board, about 1 cm away from the connector ( tested with ohmmeter ).
I didn't try to short it to test the current, but being a polyswitch I think the protection is assured.

Mandi
 

arcaphill

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usb port short circuit

The following company have the products:
TI, Fairchild, ADI, On Semi and so on!
 

arcaphill

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usb ports short circuit

Also, you can use a fuse for cost down!
 

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