Electronic – USB B, mini B, or micro B for product design

usb device

I'm trying to decide which connector I should use for a USB peripheral I'm designing. Is there a guide for choosing one?

The device is a portable electronic scoreboard that's 16"x10"x1". It will be outside, possibly in wet conditions. It will not draw power from the USB. The only thing the USB will be used for is slow terminal serial data back and forth.

Best Answer

Mini-USB is a disaster waiting to happen (in my opinion and experience).
Insertion-removal lifetime is low - one of the major factors addressed with micro-USB was an increase in cycle life.

If I was doing what you describe I would choose USB-B (ie full size) as the working choice for development and only change it if there were major reasons to. I had just this choice a few years ago and went with USB-B. The product didn't eventuate but I anticipate using it in a similar role in future.

Micro-USB is superior to Mini in many aspects. Current capacity is down in most cases but some manufacturers make (or claim) higher current versions.

Micro-USB is THE new international cellphone charging standard connector. Doesn't affect you application directly but does mean that NOT being Micro-USB compatible will prevent a few random plugins.

Regardless of what you choose, if it can get wet it should be capped in a manner that effectively gives it a formal IPxx rating that suits your need.

Mechanically, USB-B is very robust and resistant to everyday use. I have not yet seen a damaged Micro-USB connector, but they fail the-soldier proof test and probably also the hurried person in the dark test. Even USB-B would benefit from a connection guide that increases the do-it-in-the-dark connection success rate.

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