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USB-C connector: Can I use it just as a connector for another purpose?

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userx2

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Hi, I am developing a new product that requires a neat looking connector (not for general use)

A USB-C connector is being evaluated for the purpose as it is cheap, neat, and can handle the current (12V 1.5A) as well as analog signals required


This will be a custom port and custom unit, nothing to do with actual USB.

I read that the USB-C cables have a micro processor in them.
Would that be a show stopper or can USB-C connectors on cables also be done just as a dumb cable?

If this fails, then I have to revert to a USB-B connector which is much more bulky.
There really is not much choice for a nice little power / signal connector out there.
I have spent several weeks evaluating samples and all have been rejected.


Best regards
X
 

It's just a plug/socket, there are no active components in them.
Certainly you can use them but be very careful to label them as NOT for USB use. I would keep at least the ground wire on the same pin for USB and your application if possible, at least it will minimize damage if it does get plugged into a USB device.

Brian.
 

Hi,

I recommend not to use the USB connector.
If you use them, expect problems ... and you are responsible for them.

We don't know how you connect the signals/power.
But you need to expect that someone connects it to real USB devices.
In worst case you risk fire.

Klaus
 

There will not be an issue with real USB devices being plugged in.
My CPU will sense the correct device before applying power to the connector/cable.

There is really no other viable choice. Previously audio connectors were used but those cannot handle the higher current and they do not have enough signals.



So the USB cables do NOT all have microprocessors inside them?

The spec states somewhere that they "shall"...
Apparently to let the port know what capabilities the cable has current wise etc.

I was surprised to discover that yesterday!

I need to know because the prototypes will use ready made cables that will be cut and connected to the device.





Regards
X
 

I read that the USB-C cables have a micro processor in them.
Click to expand...

Reference please.

They are just cables, useful for both power and signal.
 

USB3.1 is described as a variant of USB-C with a chip on board. USB-C alone does not have it.

The idea is the cable can read voltages superimposed on the 'client' (non-PC) end and report back to the USB host. It s widely used for example in mobile phone cables that support normal or fast charging by adjusting the power source output voltage.

If you just use the plain cable and sockets it should work fine. If in doubt, use a DVM in diode test mode with probes across pairs of the pins, if there is an IC in the cable its protection diodes will show up. If the voltage isn't clamped by them it should be safe to assume it is a simple point to point cable.

Brian.
 
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    userx2

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Perhaps I am not interpreting that correctly but please enlighten me.
Click to expand...

Sorry, I did not know enough. Of course you are reading it correctly.
 

In the past, the company I work for has used SATA cables for non-SATA purposes because the signal integrity of the paths and the connectors are somewhat robust. Now, we are using USB 3.0 for the same reasons. The connections are internal to the machine so the consumer doesn't have access to them to plug a "real" SATA/USB item into them.
 

This here is also interesting:
https://www.reclaimerlabs.com/blog/2017/1/12/usb-c-for-engineers-part-2

"Cables can be electronically marked. This means there is a microcontroller inside one of the plugs, connected to the CC line. It is responsible for reporting the capabilities of the cable. "All USB Full-Featured Type-C cables shall be electronically marked." (section 4.9). Cables that only support USB2.0 do not need to be marked."


Regards
X
 

Do not forget that a user may also plug a USB3 power supply into it.
So whatever your internal processing, it may have voltages applied to the port.
 

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