The power flow is:
ADP12V (Type-C port and the 12V power input pins) → SY81012 DC/DC regulator → VPH_PWR / VPH_PERI (constant 4.2 V) → SY7120 Step Up Regulator → VCC_5V_PERI (constant 5 V for USB and other peripherals)
So, accounting for voltage drops and reliable operation of SY81012, it can handle 4.5V to 16V power input. Sorry for the incorrect infomation before.