| hi,
Tigris Chip (U2300) it is responsible for generating PP_VCC_MAIN. By default, the battery (PP_BATT_VCC) supplies this; note the pull down resistor on Q2300. If the Lightning port is connected, then Q2300 is "opens" and PP5V0_USB is used to generate PP_VCC_MAIN via the built-in Buck converter (post by Minho on ifixit portal
) |