P9243-GB / step-down buck regulator

Hi Renesas,

I am working on a wireless power Transmitter (wireless charger) P9243-GB, 

the P9243-GB via GIPO_B7, generates a PWM signal and controls the feedback pin of the step-down regulator, so I would like to know more in detail about how this affects the voltage on the feedback pin and between what ranges the output of this DC/DC change?

my intention is to use wireless charging and to be compatible with iphone at 7.5W