Among the many changes found in the iPhone 5 is the new Lightning dock connector. For months we’ve been expecting Apple to replace the aging 30-pin port in its new handset, and it did.

The change has caused a bit of controversy, because folks don’t understand why it was necessary, and they don’t know why Apple didn’t go with the more popular Micro USB connector.

As it turns out, Micro USB isn’t smart enough…

Rainer Brockerhoff, a software programmer and ex-engineer, explains Apple’s thinking (via The Loop):

“People keep asking why Apple didn’t opt for the micro-USB connector. The answer is simple: that connector isn’t smart enough. It has only 5 pins: +5V, Ground, 2 digital data pins, and a sense pin, so most of the dock connector functions wouldn’t work – only charging and syncing would. Also, the pins are so small that no current plug/connector manufacturer allows the 2A needed for iPad charging.”

There are a few other benefits to Apple’s proprietary plug as well. For one, the connector’s reversible, so it can be inserted in any way. And two, it gives Apple better control over accessories.

The swap certainly isn’t going to be painless. You’ll have to buy an adapter to use the new iPhone with any of your old dock accessories. And even then, they’re not guaranteed to work.