The iPhone 8 will reportedly come bundled with a 10W power adapter that features a USB-C connector and an integrated USB-C Power Delivery chip.

Curtis believes the USB-C Power Delivery chips built into the iPhone and 10W power adapter will be supplied by Cypress Semiconductor, likely the same CYPD2104 chip used in the new 10.5-inch iPad Pro.

We believe that in the iPhone 8, Apple likely includes Cypress Semiconductor's USB-C Power Delivery chip in the phone and an additional chip within the power brick in box (likely a new 10W, which would use a more integrated solution with Cypress Power Delivery).

Similar to the new iPad Pros, the iPhone 8 would support fast charging with a Lightning to USB-C cable connected to the new power adapter. This corroborates a report form KGI Securities analyst Ming-Chi Kuo who predicted the iPhone 8 would feature a Lightning connector with USB-C Power Delivery that enables fast charging back in March.

It's possible Apple would include a Lightning to USB-C cable with the new iPhone and perhaps a USB-C to to USB-A adapter for compatibility with older computers and power supplies.

Source: iclarified