USB charging, part 1: requirements

Thanks for posting this informative article.

Several minor corrections.
#1 : The two data carrying wires are Dp and Dn or D+ and D-, not DP and DM.

#2: There is no such thing as "USB 3.0 C-series"

There is USB Type-C, which is a third type of connector introduced in 2014. USB Type-C is intended to replace both Type-A and Type-B connectors and plugs. It is not required that USB Type-C ports support USB 3.0 or USB 3.1 data rates. In fact, many of the implementations on phones today use Type-C but only connect the receptacle to USB 2.0 Host and Device controllers, and most of the Type-C cables on the market today are USB 2.0 only, meaning they have only the base 4 wires, and none of the SuperSpeed wires.

USB Type-C and the related specification USB Power Delivery introduce much more complex and more rigidly defined power capabilities than the USB BC 1.2 you write about. It may be worthwhile for you and I to at some point to collaborate and do a more detailed explainer about USB-C and PD charging in the future!

See my explanation of USB Type-C Configuration Channel, for example : https://plus.google.com/+BensonLeung/posts/4xq4EDjXMw8

Also, my G+ collection for USB Type-C Explained :
https://plus.google.com/collection/0Vdov

Thanks!
Benson