What if I inserted micro-usb cable into usb type-c port

usb

My wife bought a new phone, and was trying to use a previous charger and complained the charger's cable did not fit. I'm an electronic engineer and so, you know, errors are not forgiven at home! I said "Don't be stupid, all the world runs on micro-usb". I tried and with a little force it entered, and even charged for a while, then it popped out.

We then noticed the new cable in the box was larger, and realized the phone has USB type C, my fault to not have checked it. So I said in fear: "Don't worry, such an important standard must have been done with retro-compatibility as first thought…". And instead no, all the info I found say the cables are incompatible.

So:

  • do you think I may have broken it?
  • why did it seem to work for a while?
  • may it be that, by chance, they designed it to be safe in case of errors like this?

EDIT
Questions were not very professional, so I rephrase:

Does USB type-C receptacle provide a limited / failsafe physical compatibility with micro-usb type-B plug?

Best Answer

If you look at the pinout of the USB C and Micro B connectors it's clear why they aren't compatible, pin count, sizing, shape. Everything is different pretty much.

enter image description here

  1. Is it broken? - It's hard to say what damage has been done. You've already said it charges, I would recommend trying to copy files to and from the device via the USB connection. If you can transfer files in both directions and charge the device I'd say you're ok.
  2. Why did it work for a while? - If you look at the pinouts of the 2 devices. There is a slight possibility that pin 1 of the USB micro B was touching pin A9 of the USB C and pin 5 of the USB micro B was touching pin A1 of the USB C. However, this is pure speculation.
  3. Were they designed with compatibility in mind? - No, they were not. The pins spacing of the two different connectors is different in terms of pitch. This was to make the USB C as compact as possible as it has 7 extra pins compared to the USB micro B.
    Also if you think about it from a design point of view. If you were to make it so a USB micro B would work in a USB C, due to the design being a non-polarised connector. You would require VCC and GND pins to be directly opposite each other, which as you can easily imagine is just asking for problems.

Edit: I've added a picture to help illustrate my last sentence if it wasn't clear at all.

enter image description here

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