The BQ28Z610 device manages its supply voltage dynamically according to operating conditions. When V_VC2 > V_{SWITCHOVER–} + V_HYS, the AFE connects an internal switch to BAT and uses this pin to supply power to its internal 1.8-V LDO, which subsequently powers all device logic and flash operations. Once VC2 decreases to V_VC2 < V_{SWITCHOVER–}, the AFE disconnects its internal switch from VC2 and connects another switch to PACK, allowing sourcing of power from a charger (if present). An external capacitor connected to PBI provides a momentary supply voltage to help guard against system brownouts due to transient short-circuit or overload events that pull VC2 below V_{SWITCHOVER–}.