Qi Charging transmitter types

Question

I am working on a Qi Transmitter project and I have found that the Qi transmitter that I am using is not able to charge Iphones and Samsung phones at the 7.5 W that it should be able to. I am using the Qi 15W capable P9242-R which is a transmitter type of MP-A2, all the 7.5W capable iphone/samsung transmitter designs are MP-A11 or MP-11a according to the Qi product search page. the P9242-R seems to charge the Iphone at a 5W rate.
I have read the Qi Spec but there doesn't seem that much of a difference between the MP-A2 and the MP-A11 transmitter design.

What is the difference between the MP-A2 and the MP-A11?
Are the MP-A11 and MP-11a the only transmitter types capable of transmitting 7.5W to iphones/samsung phones?
Are there different RX designs that only work with a certain TX designs extended power profiles(EPP)? or will all (EPP) RX work with most EPP TX designs?

Passerby · Answer

Apple decided to deviate from QI standards. 7.5W is not a normal QI rate, and you cannot get 7.5W charging without apple specific protocol. Apple devices will work at the 5W rate.
https://www.zdnet.com/article/iphone-and-android-wireless-charger-pads-which-one-is-the-best/
Samsung also did the same for their high speed charging. WPC/QI charging is limited to 5W. You need Samsung fast wireless charging v1 or v2. https://www.samsung.com/global/galaxy/what-is/fast-wireless-charging/
So your P9242-R QI 1.2 design can do 15W, but Apple and Samsung both don't care about that.

Qi Charging transmitter types

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